CONCLUSION: All should read Why my 03 is down on power

[DURAMONSTER]

Took it in and the diesel mach did a test drive. Then said this thing is a dog. He said this is not the only complaint. He called GM and talked his way up to a high authority and thay told him that liturally there are thousands of this complaint. He said that the 03s are down on power on purpose. GM would not say why. But that thay did this for a reason. The rest is no comment. This totally ****es me off. I thought GM learned a lesson on this with there previous Peice of crap motors. Apperentaly thay made a name in 01 02 and now its time to back off so there is less warrenty work. There going to **** people off with this and make them go back to f***. My dealer mach is totally cool though. He did a WOT test and it came back ok. He said it is diff than 01 02 on the peddle sensor. The 01 02 at the Quarter position will show 20% and a 03 will be 70%. Basically this is why I have just as much power at half throttle as I do at full throttle. I think this is to make the 03 show powerfull like a 01 02. It is a copout. He also checked my turbo and it is putting out 37 pounds of boost at red line. He said that was good. He told me to leave the truck and when he gets off work He was going to do everything possible to get it to run. He just cant screw with stuff for no reason during pay time. So he told me to get the vin # of a 02 that is fast stock. He was going to reprogram the truck to the 02 specs and try to trick the computer. He spent a couple of hours on it after work and it did not work Every thing he did messed up other things. After he programed the 02 stuff in he said the stereo did not work and the oil pressure gauge did not work. So after all his stuff he tried, he put it back to stock and now all is back to a dog. Then he told me to go buy a performance box. I said what about the warrenty. He said We warrenty anything. Thay warrenty dmaxes with boxes with no prob. He also said to talk to who ever you buy a box from to see if a 02 box will work instead of a 03. This might work better. He also said that to not run the truck on the high setting very much since he has seen so many come through the shop to get a oil change and find alot of diesel in the oil. The only ones that have diesel in the oil are the guys that say thay run the box on the High setting alot. So I think I have narrowed it down to buying a predetor.

[WhiteDuramax]

That really sucks. My buddy has an 03 and it seems you have to give it more throttle to equal the same repsone as mine, kind of wierd, and its not cause I have a predator, cause he has juice.

[Dmaxin]

I always thought my 03 was low on power compared to the 02 trucks i test drove. Well I quess that means we just need to get juiced!

[DURAMONSTER]

Do you like the predetor? I think thats what I want. I want to stay reliabe. The juice seems to be hard on stuff. if I have the power Ill use it. So the pred seems to be more what I want in the aspect in not hurting the truck.

[Dmaxin]

Duramonster, just currious , but why do you think the juice is harder on equipment?

[roegs]

If the 03's are really that much down on power, wouldn't GM have needed to change the published specs for HP and Torque?

[DURAMONSTER]

Dmaxin
It seems that people here that run the juice are the ones that report the tranny slippin and want the tranny upgrades. I could be wrong but it seems like a trend. It seems to be to much HP for certain parts. Tell me im wrong. Id like to run the juice. But the pred still has other options that I also want.

[RWTD]

Originally posted by DURAMONSTER:
He told me to leave the truck and when he gets off work He was going to do everything possible to get it to run. He just cant screw with stuff for no reason during pay time. So he told me to get the vin # of a 02 that is fast stock.WOW! That shows quite the devotion on his part to helping the customer! I'm glad to see that this does exist still in dealers' service departments!


He spent a couple of hours on it after work and it did not work Every thing he did messed up other things. After he programed the 02 stuff in he said the stereo did not work and the oil pressure gauge did not work.Yeah, unfortunately GM has altered some sensors and parameters from the '02 to the '03, which will keep the pcms from interchanging properly between the two.

A lot of the GM vehicles you can interchange the pcms, such as on the 99-00 Camaros, and 01-02 Camaros (01-02 didn't have EGR), just like on 87-88, and 89-93 Mustangs, you can do the same. There's almost always something that you may have to change on the pcm calibration, however, to get 1 area to function the proper way, even though some do not bother. It's a shame the '03 Duramax will not work with the '02 calibration, however. :(


So after all his stuff he tried, he put it back to stock and now all is back to a dog. Then he told me to go buy a performance box. I said what about the warrenty. He said We warrenty anything. Thay warrenty dmaxes with boxes with no prob. He also said to talk to who ever you buy a box from to see if a 02 box will work instead of a 03. This might work better.In terms of the Predator, the '03 will have their own calibration as would the '01 and '02. The Predator goes by VIN # and calibration data to determine how it needs to build its tunes.

Whichever performance product you go with I'm sure you will be happy. Good luck to you and your endeavors, and I hope that you get your truck to the level that you want it to be.

Have a great upcoming weekend!

Kind Regards...

[DMAX Daddy]

Well, if someone within a few hours drive of LA knows where we can go Dyno our trucks, Ill bring my stock 2003 to check vs a stock 2002. Im kinda curious now.....

[RWTD]

Originally posted by DMAX Daddy:
Well, if someone within a few hours drive of LA knows where we can go Dyno our trucks, Ill bring my stock 2003 to check vs a stock 2002. Im kinda curious now..... Randy, try locating a Dynojet facility in your area:

http://www.dynojet.com/maps/autodynos/ca.htm

I know that a load style dyno is best for tuning, but a Dynojet will still give you accurate readings for comparison's sake if you're gonna dyno two Dura's the same day on it.

[DURAMONSTER]

RunningWithTheDevil
Well I decided I'll go with your product. I just have to wait a little longer to purchase it due to my wedding is costing me alot of money. But it will be real soon. Thanx for replying. I was scared that I was going to have a dealer that would not cooperate, however I got lucky and he was really cool. He is also interested in becoming a member on this site after I told him about it, and that will be nice to have another tech on board.
I would be scared to Dino this truck stock.
Thx again!

[RWTD]

Originally posted by DURAMONSTER:
I just have to wait a little longer to purchase it due to my wedding is costing me alot of money.You better get it while you can. :D However, the new "Boss" would be VERY impressed if she knew you were putting the priorities first! Maybe you should show her this here post as how much you really love her. Hmmm, then again she may put her foot down when it comes time for you to whip out that creditcard, LOL, so you better not show her ;)

Good luck on the wedding, and the best wishes to your lady and you!

Sincerely...

[Nixter]

I would really have to drive an 02 to believe that there is that much difference. It wouldn't suprise me at all if they tweaked the software a little and softened it up a tad but I doubt it would be that much. In day to day driving I don't use more than 1/3 throttle and the truck feels so light it could be made of styrofoam. The only time I really lay into it is towing on grades and then it doesn't lose a step.
Also FWIW, the guys that talk about limping thier tranny with Juice are generally dragracing with Hot Juice level 4. I just installed reg Juice and have nothing but good things to say about the way it makes my truck run in level 1 and 2. I have not tried 3 or 4 yet so nothing to report. Tomorrow I will hook up for a tow and I expect to wear a grin the whole time. I was drawn to the Juice because of how it makes power right in the meat of the RPM range instead of following the stock curve. So far it has lived up to it's billing. The predator does look appealing though I have to admit. --Nick

[Maverick]

Nixter,
What are you doing this weekend? I could run my 01' 2500HD against your 03' if you want. I feel it is a pretty good runner (peppy) in stock form. You'll have to take the juice off though.
357-6317

Maybe I can drag Bush Pilot along. There's another guy in Eagle River too. Can't remenber his name though.

[ 06-05-2003, 11:58 PM: Message edited by: Maverick ]

[DMAX Daddy]

Wow, Borla is located here in Oxnard. Ill give them a call tomorrow and see if I can pop in and get a run or two in.

[Nixter]

Maverick,
That sounds like a fun, and it would really be interesting to find out how they compare. However I have a commitment to take some guys fishing in the inlet this weekend, and other folks in the Kenai the following two weekends and then probably more after that. This is what I do in the summer time, not professionally, just because I'm a single guy with two boats. Last weekend we caught 6 kings that averaged about 45 pounds each. The bigger ones should be on thier way. Remind me in the fall after general moose season, and maybe we can round up the other guys as well. --Nick ;)

[Dave Lewis]

I think the TECH 2 can read torque to the transmission. It would be interesting if one of the techs on the board (dmaxallitech) could compare the readings on an 01/02 to an 03 in similar situations. This would tells us how big of a difference there is in our trucks. This has me quite upset. I've been reading how peoples trucks have all this incredible power stock and I just dont see it. I had the dealer check my pedal position sensor and it was fine, everything checked out fine. I think my 90 K1500 with a 350 had more power than this. A Predator may be a fix but I think GM has som explaining to do to people who think they bought a truck that puts out 300 hp and 520 ft/lbs of torque (does it really???).

[AlanL]

My '03 (my first diesel) didn't feel to me like it was up to the numbers or the "buzz" about the power that the DMax should be making, but I figured that it was me and my lack of experience driving a diesel. Towing, its still much better than my 6.0 gas suburban *ever* was, but never had the short of seat of the pants push that I expected.

Fuel milage hasn't been close to what people with older trucks have been quoting either.

Since programming on the 40 HP setting with the predator this past Tuesday, I have to say that I'm feeling that sort of power and the sort of milage I would have expected stock from reading posts on this board.

I can certainly believe that the '03 trucks are down on power via the stock computer programming.

-Al

[SparkyTX]

I find this all very interesting. The 03 I test drove definitely seemed down on power compared to the 02s I drove, but my 03 seems very peppy. I have even been able to chirp the tires some on dry pavement. Not bad totally stock with the rear locker!

I have only had two fillups so far (700 miles), but have averaged 17 MPG for each. I don't consider this too bad either considering those are 100% in-town miles and each tank only averaged around 30 MPH.

Last night I drove a little over 100 miles roudtrip for my 4x4 club meeting. I reset one of the computers to calc fuel mileage etc just for that trip. For the 100+ miles, I averaged 67 MPH and 22.5 MPG. I am very satisfied with those numbers. My 96 Firebird (V6) couldn't even touch those numbers with barely half the weight and a lot better aerodynamics.

[ratlover]

Well that really tweaks me off if it true. :mad:

I to think my truck really hauls in every day driving but truthfully was expecting a bit more. It dosnt really seem down on power, just not what I expected. I have only stomped on it a few times in dry pavement going straight and was really supprised I didnt nuke the tires. I figured it was turbo spool up/only 1000k on her.

A question about boxes. If they rate an increase of 100hp that is based off a 01-02 right. If an 03 was down on power because of a factory detune it would put an 03 up to the same level as a 01-02 with the same adder right? It wouldnt just add say a 100hp to the lower 03 output correct?

[tophog]

Originally posted by ratlover:
A question about boxes. If they rate an increase of 100hp that is based off a 01-02 right. If an 03 was down on power because of a factory detune it would put an 03 up to the same level as a 01-02 with the same adder right? It wouldnt just add say a 100hp to the lower 03 output correct? I was just about to post the same question as I too have an 03 with 1600 miles. Based on all the Duramax power hype I've been reading I have been a little disappointed in my truck ... like several have said ... not what I had expected, but then again I don't have anything to compare except an 02' 6.0L gasser and that's no comparison.

Have been trying to talk myself into believing the computer has a 1K or so programmed break-in. I would be happier knowing the Juice would "restore" an 03 to the same level as 01/02 trucks. smile.gif

[Dave Lewis]

Why should we have to spend the extra money to get our trucks to the level of the 01/02's if they are still rated the same?? I bought a truck that was supposed to have 300 hp and 520 ft/lbs of torque. The question would be does it??

JK,
Do you have any experience between the 01/02 -03 trucks?

[ 06-06-2003, 09:55 AM: Message edited by: Dave Lewis ]

[Brad Pelot]

I have had a 2001 and a 2003, they have exactly the same amount of power. I had the 01 for about 40000 miles many of them stock and many with the juice. I left the juice off of the 03 for the first couple of months. Stock these two trucks pulled the same load at the same speed up the same hill several times. If there is a difference in these trucks it is extremely small.

[Dmaxin]

Well I am glad i am not the only one who noticed a little less go in the 03's. I get great mileage and the truck runs smooth but i was worried something was wrong with it. I would like to see a dyno comparison (sp?) between a 01 or 02 and a 03 that is down on power. Quick question about power boxes. Dont the Preditor and the Juice pretty much do the same thing as far as timming and injector pulse and width? Neither raises fuel line pressure, do they? Thanks

[ratlover]

Originally posted by Dave Lewis:
Why should we have to spend the extra money to get our trucks to the level of the 01/02's if they are still rated the same?? I bought a truck that was supposed to have 300 hp and 520 ft/lbs of torque. They question would be does it??

JK,
Do you have any experience between the 01/02 -03 trucks? Your right, we shouldnt have to do a damn thing to get 300hp and 520ft/lbs of torque.

Although a box would definatly give you more than that.

Thats nice that someone says they are the same. How do they compare at WOT?

I think this topic isnt going to sit well with alot of people. Hopefully its misinformation somewere.

Didnt they do an update to the alli? Or is it the same thing as was introduced? I know there have been some program updates to fix "bussy shifting" but other than that are there any changes? If the alli is holding fine at stock levels and they did some slight improvements why would they turn around and lower the power to help save the drivline? :confused: Cant tell me there have been problems with the 11.5 rear. That is a beefy sucker. What else are they having a problem with?

Maybe you could run another 03 and an 01 or 02? Be a good excuse to do a bit of testing, in the name of sience of course tongue.gif Or barrow a g tech?

Inquiring minds want to know ;)

[Kennedy]

Dunno, we took one to 390's (IIRC) with one box and 413 with a second which is more than the Allison could handle in 4th gear...

[More Power]

Never take the word of one technician as gospel, regarding anything to do with these trucks.

Last September, we ran an '03 GMC CC D/A on the same hill with a 10K trailer that we ran all previous model year Duramax trucks on. The result was exactly the same performance. Those who were at last year's Pull-Off event know this.

We'll be running another '03 on that same hill in about a week, during Pull-Off 2003. We'll also run a new Ford & Dodge.

MP

[a64pilot]

DURAMONSTER,
IMHO it dosen't matter where the power comes from Juice , TST etc. If it's more than the tranny can handle, it will limp. The reason you are hearing more about Juice limping the tranny is two fold. The hot version makes enough power to do it and there are more of them in this forum than any other power adder that adds enough to slip the tranny. More boxes will result in more reported problems, it does not mean there is more of a problem than with any other box.

[Kennedy]

I also think that there is a lot of "the grass is greener" going on as well. I've swapped modules and thought one was pretty nice till I went back to the Juice.

There are far and away, more Juice modules out there than any other. The Juice still gets the most power SAFELY to the wheels by modulating output to minimize/control slippage.

My truck has been quite lazy in 5th gear as of late. Kind of annoying, but the reality is that the Juice is feeding it all it can handle. Put a non modulating box on it like the TST Comp. and it perks right up, BUT limps quite easily. Those who think they need the Comp. version and have a stock trans had better think again. You can always upgrade...

[ 06-06-2003, 11:37 AM: Message edited by: kennedy ]

[SS396]

MP I will volunteer mine the following weekend, if you don't mind a newbie running the hill.

Mine is bone stock except the air filter.

[DURAMONSTER]

SparkyTX
Your truck is definantly down on power if it only chirps them. My brothers stock dmax 02 cc 4x4 2500 lb will roast the tires for about 100 feet on rough dry pavement. A totely stock 02. My dads 02 3500 cc 4x4 dually stock will roast them for about 20 feet due to dually traction. My brothers best friend has a 02 2500 cc 4x4 lb that roasts them as far as my brothers, and it is also stock. I bought my 03 expecting the same. That did not happen. Your truck bieng a sb should get with it evan more so. Some people here are saying that there 03 had the same power as there 02, thay are lucky. Maybe a change was made in a cirtain cutoff date and some 03s will have power as 02 do. We should find the manu date on the trucks that are saying this.

[DURAMONSTER]

More Power
A tech listened to the phone conversation the diesel tech had on the phone after working his way up to managment at GM. This came right from the horses mouth. He said He would show me and let me read the GM computer that is linked to GM that has THOUSANDS of complaints of this prob. I said thats alright I know what there all going to say. GM was keeping it hush hush why thay did this and would not release any info to him. The little he did get he dragged it out of them. He also told me to get rid of the cat on the exhaust since there is and never will be any smog testing on the 03. It is on there to get things started and do some of there own testing since in I think he said the year 06 all diesels of 06 and up will be smoged and checked. Thay are trying to get there ducks in order for the 06 trucks.

[gene smith]

yall please excuse cause i am new to this page but i just became the proud owner of new 2003 d/a dulley and am very pleased with all except the milage, the co i work for has a 01 with 135k that my o3 will run an pull with, my 03 has only 1200 miles and i love it, my question does anyone out there have any faith in amsoil for this engine thank you- geno

[BADMAX]

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

[BADMAX]

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smile.gif smile.gif smile.gif

[Very Old Dog]

I guess I do not understand. I cannot tell if I have more power on my 03 or less power. What I do know is that I drive the vehicle stock without any modifications and that it has plenty of power and accelerates very steadily to 60 miles per hour smoothly and without hesitation. I do not lead-foot the accelerator and drive probably conservatively by the standards of the posters. I do know this by comparison: I have owned 4 Dodge Cummins diesels, 3 automatics and one HO 6 speed standard which was heavily modified. Without question, the Duramax and Allison combination is far superior to the automatic Cummins. Please do not understand, the Cummins were excellent, never had a problem and were traded in without a hitch for new one. They were stock. The 6 speed HO had a guarges, VA box, 4 inch exhaust, turbo boost module from Performance Systems, Bosch 275 injectors and a South Bend Clutch good for a 1000 lbs. of torque. The engine was dynoed at a little over 300HP and 750 foot lbs. of torque. It was a hauling beast and was used to tote a 15,000lb fifth wheel which I ran in cruise control over the mountain passes of Colorado, NM, and Wymoming and never down shifted unless the speed required.

To make the point, the Duramax 03 seems to be just as quick if not more so than the 6 speed HO Cummins even with all the modifications. If the 02's are quicker, and the sensors are bad in the 03's, I cannot tell. I never floor this animal anyway. Mileage is excellent at 18.5 in the city and 20 on the highway. I do not know how it tows because I since have sold my fifth wheel last Winter. I may obtain a 26ft. trailer in the future and I cannot see where towing this 7000lb GVWR will be a problem.

Perhaps, some of you can provide information to let us know how to tell if there is a sensor problem. My unit was built in late February or early March and the dealer received it in April. I purchased the unit in late April. I do not have a clue as to when engineering changes are applied to vehicles in production and this may be a factor. All I know, is that this vehicle, with engine transmission combination after 3000 miles performs quite admirably and I am pleased.

I admit that I had apprehensions since I had excellent performance from the Cummins, but the automatic transmission in the Duramax and the engine itself is outstanding. Perhaps, ignorance is bliss.

[David Proske]

I think we should post some 0-60 numbers of stock 02 and 03 trucks and compare the difference. I read all the posts of stock tire smoking performance, mine sure isn't like that unless I act like a fool and powerbrake it.

I am obtaining a G-tech and will post some numbers.

[Kennedy]

These trucks are not going to smoke the tires w/o spoling some boost unless VERY light in the rear, and/or MEGA bombed...

I think that is what is tripping guys up. They think the tires will burn with mashing the pedal, and it's just not going to happen...

[Tsckey]

I wonder if there is a reverse placebo effect going on here. Somebody suggests the '01s and '02s have more zip and all of us with '03s are suddenly remembering the last time we punched it and only got acceleration with no tire smoke. Seems to me I remember some old, pre-03 posts where individuals said that unless they brake-torqued their engines and spooled the turbo up a tad before dumping the brakes that's all they got, too. But memory can be an indifferent tool.

The heaviest load I've towed so far is about 6,000lbs and that only included one grade of any significance, but it was a doozy. Entering the base of the climb at 55 in cruise the truck lost speed to about 51-52, downshifted then immediately accelerated to 57, or so until we crested the hill then upshifted to 5th. I don't know if it would have downshifted at all had I been peddling it myself. I was just curious to see what it would do in cruise. I wasn't surprised at the downshift considering this particular climb and starting out so low in the power band. Would an earlier version have done better? Beats me. I hope somebody gets some direct comparision data to supplement MP's observations. I need to know whether my truck needs a pill.

TC

[More Power]

All of the '03's we've driven make power equal to the '01-'02 models. We proved this on the 6% grade pulling a 10K trailer - in a measured mile - from a dead stop.. Result - virtually identical elapsed time and top speed.

Since the beginning, there have been an occasional owner who complained about his truck being down on power. I've heard this about '01 through the '03 models.... Actually pretty rare though.

If there was an endemic power problem with the '03 models, this BB would be filled with complaints, and I would receive a lot of email about it.... This isn't happening.... It's an "easy out" for a tech to say they all run that way. Have your tech contact me if he wants to learn more about it.

As many of you have already heard, GM will uprate the powertrain programming for the next model year. The biggest change will occur with the January 2004 calendar year powertrain. The engine will be significantly more powerful (reports range from 40-60 additional horsepower), but only in 3rd & 4th gears. In 1st, 2nd and OD, reports indicate there will be no change from present. I fully suspect there'll be lots of discussion about power issues in January 2004, and a perceived lack of power increase for the newest models. Those who tow heavy will see a dramatic increase. Those who hot-rod might not see as much of an improvement.

MP

[James S]

Hey There,

Let me jump in and give you my two cents worth. Kennedy, and Eric, correct me if i am wrong. These trucks take a LONG TIME to PROPERLY break in. When I got my 2500HD crew cab, long box four by four, a few months ago, I put about a thousand kilometres on it, then did three trips to Vancouver from here in Edmonton, going about 120 kilometres an hour over the Rockies. I also have done some towing of a enclosed trailer with three thousand pounds of lumber in it, several times, varying the speeds, accelerating hard, letting the temperatures cool down, and then repeating. Acording to the Canadian Duramax rep who I have met and know personally, it will take about twenty thousand miles, thirty-five thousand kilometres, to break in this STOCK engine. If I didn't do this, it could take as much as fifty-thousand kilometres of just casual driving to break it in. Those of you who have added performance parts to your engine, COULD experience problems with your engine, tranny, power, torque, fuel milage, etc. After leaving my engine stock, I am averaging twenty-five to twenty-seven miles per imperial gallon on the highway. Yes you read it right, and twenty-two miles per imperial gallon in town. If I upgrade the filters, and exhaust, and get EVEN BETTER milage, power, torque, etc, that would be great, but I am certainly not putting on a box. I am not meaning to chew your heads off, but just letting you know, don't forget that these engines don't break in over night. Read the article, "BREAKING IN A DIESEL ENGINE", and it will outline this. It seems that alot of the problems, people on the forum are having, are from improper breaking in of the engine. Good luck and I look forward to any responses, but again, no hard feelings meant, just a word of caution.

James

[Burner]

James, I agree on proper break-in for this diesel. However, these engines are not warranted for 500k miles like big trucks so most people would like a little safety net in their application, hence early power mods. Yes, it is not right but most people will protect "No 1" first, whatever the cost. Therefore we will have many people that will enhance the truck before 10,000 miles, well before break-in. The ignorance of not knowing break-in, EGT temps, dirty fuel, tranny slipping (i.e., when your "extra" HP is not getting to the ground) is and will be common with this truck as others. In time persons with this type truck will educate themselves as to what is good and bad for their truck. If they choose to be "stupid" and stack power modules or apply modules that exceed their drive train that is their choice. However, there are a limited few that really don't care about the warranty or "break-in" hours. These people just want "POWER" and the ability to get it to the ground.

Generally speaking, if you can afford one of these new trucks... you don't really need a warranty and if you do or are suspect of having "power mod" problems then you will not add them. I think that 99.99% of The Diesel Page (http://thedieselpage.com) members are intelligent enough to make a prognosis or decision on "power" mods. ;)


Burner--------> :D

-----Getting back to the topic.------

The trucks "overall" output is the same. On the Dyno or on the street they are the same. The Dyno shows the same HP and TQ. Heads up in a drag race they are the same. They are the same pulling a load up hill, down hill and on flat ground. The only difference that people will notice is truly in the "porgraming" and transmission. The programing is really smootheeeeeee in the 03's and the clutches are made of a different material. The sensation for 03 owners is that the truck is "slow" for a 7,000 lb truck with 300HP and 520lbs. of TQ. Is that 23lbs of weight per HP? What is a Vett?
GM has modulated the program and tranny but we are still getting 240+HP and 440+TQ to the ground. I think they are "updating" the power curves, torque mgt and relay input so that the trucks can be "adjusted" closer to the 340HP mark, 04' figures. Bascily, after next year or so we should be able to toodle off down to the "dealer" and get a "reflash" power upgrade. :D :D :D

[ 06-07-2003, 01:23 PM: Message edited by: Burner ]

[P40murf]

I traded a '01 D/A for a '03 and could tell immediately it couldn't pull my 12,000# 5th wheel like the '01. Also the mileage went from 10 mph to 8.5 mph under identical towing conditions. I took it to the dealer, hoping it was the throttle position sensor, but it wsn't. The service manager called GMC and was told the '03 was programmed to meet the latest EPA requirements, causing a power loss. They said they can power it up, if only EPA would give permission.

[tophog]

I'm about ready to power my 03' up with with approval from EPA (Extra Power Accessory) called the "Juice" smile.gif

[More Power]

We ran another stock '03 during the Pull-Off last weekend.

This confirmed once again, that the '03 models are not down on power.

MP

[LanceW]

mp, I think we need to update this site with the little emoticon that has a little smile.gif banging his head against the wall... the bike forum I'm on has 'em...

[Kevin West]

Well i bought an 03 3500 in dec of 02. I live Near Philly PA my dealer went to massachusetts to get my truck for me. They happend to have a truck simiuler to what i was looking for. any way it came with the emissions control for thoes states on it. now i have been towing a 28 foot enclosed trailer (alot) with various cars in it but the usually will weigh about 3-4 thousand pounds total 8000 pounds my truck will slow to a 45 MPH crawl going up hills near pittsberg area. Fuel milage im gettin 9 - 10 mpg depending if im loded or not.(9 with car 10 just trailer) my truck is compleatly stock. except for a truck cap and turbo wing to deflect air (wich by the way didnt help in gaining any beter MPG's)iv tried adjusting the wing that didnt help either.my truck curently has 32 thousand miles on it. so is this normale or am i lacking power its my first duramax so i dont know..

[JoeyD]

Jim, Was the 03 you ran from GM or a local dealer? It is odd that more than a few that have had 01's and now 03's say the power is down. I remember a post you made about the 04's having more power but not in all gears, could the 03's have something similar?

If anyone thinkstheir 03 is down on power run it on a dyno. GM is still advertising 300 HP and if thats not what you got then it would be false addvertising.

[afp]

All right guys, this isssue is all about feelings, and contrary to the liberal crap and "sensitive men of the 80s junk" that is out there, we as MEN need to go by what we THINK, not what we feel. ;) ;) ;) ;)

I drag raced for several years. One thing you cannot rely on is "seat of the pants" feel. It just isn't reliable. Some of the best ETs I posted were from very smooth smooth runs.

If you guys remember, the earlier versions of Juice "felt" stronger than the later versions, but the power output was the same.

Chances are, what we have here is, is a difference in throttle response betwen the 01/02 and the 03s. Based on what has been described, it sounds to me that the 03s need more pedal to get the same acceleration feel as the earlier trucks. It will be interesting when we have guys do head-to-head runs with 03s vs 01/02s, as well as see some times and dyno runs.

Also, JK is right. Spinning tires is not a measure of power. It is mostly a measure of traction. Rough roads and hot roads (where the oil starts coming up out of the asphalt) will give lots of wheel spin. A dragstrip prepared with VHT will be very stick and there will be less wheelspin. Having said that, if two trucks with the same tire configuration on the same stretch of road at the same time do launches, the truck with the most power maight have the most wheelspin. Maybe.

BTW, I have had ZERO problems with my Juice 4.0.

Blaine

[ 06-22-2003, 07:28 PM: Message edited by: afp ]

[SS396]

Joey, the '03 that was run was mine, bone stock 10K miles on the truck. No power braking, just foot to the floor from a dead stop in 3rd gear (Allison). Top speed 55mph on the rev limiter, doubt that it would have shifted into 4th.

[More Power]

DMAX and GM Powertrain have modified the engine control programming each year since 2001, to maintain the 300/520 rating. The additional emissions control each year do affect power, but new engine programming restores anything lost.

Modifying drivetrain programming could also be possible, which could produce a different "feel". As mentioned above, this does not mean less power - just different.

We've learned the last couple of Pull-Off events that on this hill with a 10K trailer, the best performance with a stock D/A truck comes from selecting #3 with the gear selector and running in Tow/Haul. The truck will run to the governor at about 55 mph, and stay there for the last portion of the hill. Running in "OD" will allow the transmission to upshift to 4th (direct) before crossing the mile, and the truck then loses a couple mph.

With a 6-speed stock truck, staying in 4th (also at the governor) produces the best top speed on this hill.

MP

[MaxDiesel]

Does this statement have legs?
"He also said that to not run the truck on the high setting very much since he has seen so many come through the shop to get a oil change and find alot of diesel in the oil. The only ones that have diesel in the oil are the guys that say thay run the box on the High setting alot."

I keep my juice on 4 all the time. Don't on it a lot, but sometimes going on the freeway and such I'll punch it and I blow black smoke for as long as I'm "on it". The EGT's will get to 1200-1250 and then I'm at 75.

Any issues with that?

[P40murf]

As I posted above, my 2003 D/A doesn't pull as strongly as my previous identical 2001 over the same road and the same 12K 5er. Also, mpg is down. The GMC customer service rep said they know the power is down due to EPA requirements. He also said they know they must do something to compete with the latest Fords and Dodges. The 2004 Duramax will be programmed identically as the 2003 at this point. If GMC is later able to get the 2004 power up, the "fix" will be made available for the 2003s. I'm no expert, as some of you most obviously are, and maybe GMC is blowing smoke at me, but I just wanted to pass on what I've been told.

[tysmith]

This won't be the case for everyone, but in my experience, yeah, my '03 seems a bit slower than my '01. However, my '01 had 54000 on the clock and was just starting to get loose. These trucks are so tight new, after we trade in we expect to have the same power. I've owned 10 diesel vehicles, Dodges, GM's, Volvo's, etc..
They all get better with age. My '01 Dodge HO 6 spd with 78000 is finally getting sweet to drive. Patience is a virtue...
FWIW, the dealer said there WAS some tranny re-programming for '03...

Ty

[DURAMONSTER]

I just know that my truck is down right embarrasing on a hill with a little load. I have to hit the od lock out before every hill just to not fall under about 40 mph. It will do about 49 mph on hills with my open car trailer and not much on it. It seems to be getting worse maybe. I need to dyno this thing for some proof. Im tired of it and am serously looking at fords now. I had a new ford pass me on a hill towing a huge 5th wheel that was prob more than twice the weight I had. I couldnt evan look at the guy I was so emberrased. :( I need to use a dyno.

[FisHn2DMax]

I too really thought my Stock 03 was down on power compared to my brothers 02. That was until last weekend when we pulled a long high altitude 7% mountain pass with my 9K lb 5'er. My brothers 02 Dmax was in front of me with the exact same 5'er. We were both in tow/haul mode. at first he seemed to pull away from me, then mine downshifted and I pulled right up to his bumper all the way up the 8 miles of 6-7% grade and at 56 MPH. We both had the pedal all the way to the floor. His 02 had 32K miles, my 03 had 7K miles. Both trucks seem to have exactly EQUAL Stock power!

Overall, the 03's have same power, but it seems to be delivered differently than previous years. The 01, 02 seem stronger at lower RPMS, but once the 03 needs to deliver, it's right in there with the 01, 02's!

BTW, we both passed a pair of Ford 7.3's towing much smaller trailers up the mountain pass. Should have seen their faces as we blew past them! :eek:

[ 07-12-2003, 12:46 PM: Message edited by: FisHn2DMax ]

[Bigwheel]

DURAMONSTER:
I guess was I was trying to say earlier, then editing my reply, what for some odd reason would we after spending $40,000 on a new DMAX, and needing a Predator, or Juice???? My 2002 DMAX got blow'n by a 2000 Ford power joke while we both were pulling 6 place snomobile trailers, he was totally stock, so am I. I have a real hard time understanding what this DMAX is SUPPOSE to be able to produce??, I am new to this as a newbie diesel owner. Funny as this can be, I went to the Black Hills last week with my buddy and family, he drove his 98 Dodge with a cummins that had 185,000 miles on it, we went through the hills and hit temps at 100 degrees, and he pulled his 34 foot 5th wheel without even a glitch and bucking some pretty hard winds. Buy the way his dodge has only 190 horse power!. Maybe someone can explain that we need Juice to produce what should be able done stock??, I don't mean to get some ruffled here, just say'n, "now who do I trust or believe?"

[ 07-12-2003, 07:52 PM: Message edited by: Bigwheel ]

[Lone Eagle]

And what would your point be Bigwheel? Later! Lone Eagle ;)

[Bigwheel]

Lone Eagle:
pretty sad to hear someone complain about lack of power, and go all the way to the top to try to solve a situation, but it's easier to try to bull the customer and not be truthful. Why? Just like when I brought my truck into the stealer to figure out what was wrong with my DMAX, they look at you and just try to talk you through it and say it's normal, no big deal, I asked questions, and they could not even give me any answers. I told my Tech about this web site and he blew me off. It's just a bad feeling when I read on this page ends up a different story at the stealer. Sorry to say it like it is, but until you loose your truck to a problem, or warranty issue, then you'll get it.

Opps I forgot to add this:
I have not once received any notices regarding upgrades, service information or news letters regarding some issues, like what's been brought up here. I mentioned to my tech about some of the upgrades spoken here, and he said, if they don't get an error code, they leave it alone..
I guess I'm just confused..... :rolleyes: :confused:

[ 07-12-2003, 08:53 PM: Message edited by: Bigwheel ]

[Lone Eagle]

Find another dealer. The tech and service manager at my dealership appreciate the info I give them. Later! Lone Eagle ;)

[DURAMONSTER]

Fish2dmax
I dont think you read this whole thing. My brother had a huge camper and a big boat and my dad had a big boat. Both 02 crew cab 4x4 maxs. I had a little load and on a long steep grade thay went out of sight. But the biggest proof is GM themselves said thay did detune the 03s. So how could you people keep saying crap like it just feels different or the peddle counter is just diff. All your doing is kidding yourselves. Some whare some how im going to get this thing dyno'd and shove this $48,800 truck up GMs ass and buy another 454 or powerstroke 6.0. Sorry I just am ****ed when people dont read the whole thing before thay reply to a topic. Oh but wait, It just feels diff. :D

[More Power]

DURAMONSTER,

Three things...

1- Harsh language isn't required.

2- What official documents do you have that show GM detuned the 2003 model year Duramax 6600?

3- Like I've mentioned before here in this thread, when pulling a 10,000 lb trailer up a 6% grade from standing start, the '03 models deliver almost exactly the same top speed at the one-mile point as the 2001 & 2002 models.

This proves the 2003 models are just as powerful. We've been running Duramax 6600 powered trucks every year since 1999 up the same hill with the same weight trailer. (We had a GM prototype here in Montana a year before production models were available.)

Now, it's entirely possible your truck is down on power. A dirty air filter, clogged fuel filter, or some other variance is causing your truck to perform the way it does, but it is not because "ALL" 2003 models are down on power.

MP

[ 07-14-2003, 09:09 PM: Message edited by: More Power ]

[DURAMONSTER]

Bigwheels
I agree. However there are some 03s That seem to run good. But the majority is lacking. My tech has plenty of proof of that on the GM complaints in the system that I talked about on the previous page. Dont get me wrong people. It is the most luxurious truck Ive had in my possesion. I get a new truck every 3 years and this is bar none the most well built truck on the market twice over. However I think if thay are going to change power programming then thay legally should tell the buyer the new power specs. Now I know why in the ford VSs chevy commercial the ford wins. The chevy was a 03 if you look at it. Hell even ford knows the truth about the 03s. One more note I have 2 snowmobiles and theres no waight there however I havent towed them yet, I sure hope the "DOG" ( thats my new tucks name that all my friend gave it) will pull the hills at 65 with those at least.

[DURAMONSTER]

More Power
Im sorry I just am flustered that people keep telling me and alot of other people on here that it just feels diff.
On the filter prob. The truck has a new k&n in it and the other filter looks brand new. the truck only has 5,200 on it. My wife and I struggle to make the payments on this truck and it wont out pull my 454 99.
Ill calm down now. But untill you make $844 a month payments and go up a hill at 49 mph youll want awnsers to.

[Lone Eagle]

Like I said: Find another dealer before you have a cardiac. Some dealerships blow smoke when they don't have techs that know our trucks. I haven't driven an 03 but I am going to tomorrow. My truck didn't really feel strong until about 7500 miles but it would blow the doors off the 454s and PSDs the day I bought it. Hope you get your running. Later! Lone Eagle

[More Power]

Even if your dealer tech isn't quite up to speed, you can ask him to document things like fuel-rate, rail pressure, boost pressure and a select few engine sensors while the engine at full load (full pedal run).

This could give an enterprising young tech some insight into what's going on. If not, post the data here.....

MP

[DURAMONSTER]

More Power
That sounds like a good idea. As soon as I get a chance Ill do that. Thanx.

[Bigwheel]

Morepower:

" The Duramax diesel, which produces 300 hp and 520 lb-ft of torque, was claimed by GM to be the most powerful diesel ever produced for a pickup truck. It also boasts better fuel economy than its predecessor, a 6.5-litre. It also offers high durability, rated to 320,000 km, twice what previous engines were designed for".

Since this was a quote from GM, this truck should meet what they say it sould produce, or is that not totally the truth?? My truck better DYNO 300 HP, or somethings wrong....

I don't think we mean to start issues or make accusations here, but some people, like myself have been given the brush-off from the dealer, and it ends up giving us a bad feeling on who to trust. That's why I signed up here for your support and your help and understanding....... :rolleyes: :( :confused:
Thanks!!! smile.gif :cool:

[FisHn2DMax]

DuraMonster

Please allow me to respond to your personal diatribe!
_______________________________________________

FishN2Dmax, I dont think you read this whole thing. My brother had a huge camper and a big boat and my dad had a big boat. Both 02 crew cab 4x4 maxs. I had a little load and on a long steep grade thay went out of sight. But the biggest proof is GM themselves said thay did detune the 03s. So how could you people keep saying crap like it just feels different or the peddle counter is just diff. All your doing is kidding yourselves. Some whare some how im going to get this thing dyno'd and shove this $48,800 truck up GMs ass and buy another 454 or powerstroke 6.0. Sorry I just am ****ed when people dont read the whole thing before thay reply to a topic. Oh but wait, It just feels diff.
_______________________________________________

DuraMonster,
I did read the WHOLE topic and I'm sorry you're having a power issue with your 03 truck! However, I truly don't have a problem with the DuraMax power in my $48,000 03 truck! You have the right to complain to GM, and it appears you have. I too have the right to share my personal experience and I did without discrediting you or anyone else. Again, I'm sorry you have a power problem and you feel GM is trying to pull the wool over on the 03 owners. In the end, you might be right??? However, until there is undisputable proof and detailed facts presented, you'd be wise to keep your emotions in check and not attack those here with differing experience or opinions other than yours! :(

My best wishes to you in finding the REAL answers to your 03 power problems.

;)

[drthv8r]

"He also checked my turbo and it is putting out 37 pounds of boost at red line. He said that was good."

Ok am I missing something here? Doesn't this seem a tad bit high? I thought even with a plugged wastegate around 30 PSI was about max.

[SparkyTX]

Originally posted by Bigwheel:

" The Duramax diesel, which produces 300 hp and 520 lb-ft of torque, was claimed by GM to be the most powerful diesel ever produced for a pickup truck. It also boasts better fuel economy than its predecessor, a 6.5-litre. It also offers high durability, rated to 320,000 km, twice what previous engines were designed for".

Since this was a quote from GM, this truck should meet what they say it sould produce, or is that not totally the truth?? My truck better DYNO 300 HP, or somethings wrong....

First off, something to keep in mind... HP and torque ratings are for the engine. This does NOT mean you will get 300HP/520 lb ft to the ground. That is flywheel ratings. That is industry standard. You will not get that at your rear wheels on the dyno.

Secondly, I have to agree with what several others on here have said. No one can faithfully vouch that ALL '03s are impacted. I have an '03 that I just took on a 2500 mile roundtrip to the mountains of Colorado. The trip started with only 2500 miles on the truck. This trip was towing my 3500# 17 foot pop-up. Not the heaviest, but heavy enough that would reveal a lack of power up some of those passes.

Raton pass: No problem at all. Ran at 65 MPH with EGTs around 1050 until having to slow for the construction near the top.

Cottonwood and Independence passes: Again, no problems. Only thing that slowed me down was the cornering!

Trout Creek Pass: Lower pass (9200'), but the truck rocked. This pass is one lane each way. I was able to slow to about 40 (behind an older motorhome) and still be able to safely pop out and pass with no issues whatsoever.

Meanwhile... I get around 16-17 MPG around town unloaded. I got 20-21 around town in the mountains unloaded. Got 17 MPG towing through the mountains (averaged 50 MPH during that stretch per the DIC). Got 16 MPG towing home through storms. Again, the DIC reported an average of 67 MPH through that stretch.

Some '03s may be down on power just like some 6.0 Furds have power, but I can definitely chime in that not all '03s are impacted. :rolleyes:

[conradv]

No, they're not all impacted, as I had no trouble going over the continental divide with my '03 CC LB with bed full and pulling a full trailer.

Searching this site for 0-60 times, etc..., I find that my stock '03 is exactly the board average, if not better.

[Bigwheel]

SparkyTX:
Ok, I guess I can stand corrected in regards to the HP and Torq rating, as to the industry standard states, but after I got my a$$ handed to me by both a power joke and a cummon's, I have not personally met anybody in my area, with some proof with a DMAX that's stock, totally stock, that can be amased at pulling some real weight.
My 1st test: My power joke buddy ( 2000 7.3 cc,lb ) went on snomobiling trip, and we both hooked up a 6 place snomobile trailers, with 6 sleds and 5 overweight ditch riders, we took of for Colorado, we through some steep grades, and we lined them up, and he went by like I had the brakes on. Now I don't understand, we're not talking 5th wheel weight here, but I got razzed the entire trip. 2nd test: My other buddy with a 2003 Dodge/HO Cummins, we were going down freeway at 65-70, he had 15 sheets of dura'rock in the box, no trailer, and I was totally empty, no trailer, counted to 3 then I watched him take away like I was standing still, and he could have easily gone well over 105 mph. I thnk these are some easy apples to apples ranges for some power tests, I know for a fact that the others are totally stock, I just don't understand why there's such a difference in what's happing to me and what's reporting here, without some upgrades in exhaust, and so on. After getting both these guy's all fired up on how this truck was going to pull. I've taken my truck in for some dirty fuel possibly, had fuel filter changed, they checked for codes and found none, they said it's ok. But it's been a few months since I've been in. Gonna take it in and get DYNO'ed this Friday, but not sure where that's going to take me. I pick'ed my truck last August, toward the end of the month. Thanks.
:rolleyes: :confused: tongue.gif :eek:

[a64pilot]

Bigwheel,
Somethings wrong, I don't have a clue as to what. I ran my truck totally stock for quite some time and have not had the experience you have.

[Bigwheel]

a64pilot:
Yea, I think I'm gonna be looking at some injector issues, milage is way down, not running the greatest, it's been 3 months since it's been in the shop, it's got to be something. I'm getting a tuck-under hitch installed tomorrow, have appointment to get truck checked-out on monday. After that's all done, gonna hook up my buddies 30 ft 5th wheel and take it for a weekend trip. I do love this truck!, it's awesome, just some little things may need to be worked out. Thanks. :cool: smile.gif

[kerry witherspoon]

Well i have a 2002 with a preditor one of the first ,never have been able to get my trany into limp mode.Very happy with the power ,thought about upgrading the preditor but havent yet. My neighbor bought 2003 same as my 2002 thought it lacked power i drove it thought so too,we both tow f-wheel trailers so one weekend we swaped trucks i pulled my trailer with his he used my truck. his truck pulled diferently but same speed and power on hills i always drive my conclusion is same power just different pedal position to get it otherwise the same.I admit it felt diferent less power but on same hills pulled same speed passed just as well just seemed like i was using more pedal to do it.

[kraemerf]

My '03 is running great! Not down on power at all...

[DIESELMAX403]

:confused: I have read all the postings on this topic, and I cannot draw a conclusion. Some say the power is the same for all years, and some say it is definitely not. Some say they can spin tires while others cannot even chirp them. While I think some stories lack some vital details/facts to support their statements, I believe there is something to this topic and it should not be blown off.

As for my truck experience, I feel my '03 is lacking power. While I had never driven a D/A before I purchased one in May, my '03 seems to be missing some get up and go. I base this on what I have read, what I have discussed with other owners and most importantly what I feel when I hold the pedal to the floor from 0-60. I know my truck is not broken in yet, but I am not expecting a whole lot of power increase with 10K or so.

I have already taken it back to the dealer for a look. They say its OK, but that doesn't put me at rest. However, before I get too upset, I am going to get this thing dyno'd.

Does anyone know a reliable place to get my truck dyno'd for a reasonable cost? I live just north of Houston, Texas.

[Jomar]

03`s lack of power my A$$. I know one 03 that`s not and it belongs to my youngest son. We lined up three times today and from a dead stand still we floored it and all three times he was about 1 1/2 lenghts ahead of me when we shut them down at about 70mph.The trucks are practically identical, even the grill guards, except his is shaped a little different since mine is an 02. My oldest son was also here with his 01 GMC and he could stay up with the 03 but not get ahead. I don`t know what the problems are some of you are having, and I`m not saying that you are not having a power loss, but I will go along with MP and say that from the results I`ve seen, GM is`nt producing under powdered trucks on purpose. From the problems my FO#D and Dod#$ friends are having, I`m sure glad I have a DURAMAX !!!!!


Jomar

[trout49]

I have one of the first 03's that was delivered in the state of Illinois. At least that's what my dealer told me. I took delivery on July 18th or 19th. 2002. I too thought at first that this truck was down on power after reading all the posts here about how incredible the Duramax is for almost a year before I bought it. It was like a dog taking of from a stop.So I put an amsoil air filter on it and noticed a bit better throttle response. Not anything earth shattering, but it seemed to just "breath" better, and, as JK has said many times, you have to move more air to get more power. I next put on a 4" exhaust. That is the extent of the performance mods I have made to my baby. It made a world of difference.
I tow a 36' Teton fifth wheel, and yes I am over weight rolling down the road. Let's just say I am well over 20k lbs. combined truck and trailer. I just got back from vacation in Wyoming where there are some pretty good grades. We went up Snowy Range pass 10,800ft, a 7% grade, in third gear, at 45&50 mph without a problem. And on the interstate it would cruise 65&70mph in overdrive.
Now I didn't tell you all that to brag. I just wanted to say, with just a couple of mods I was able to unleash somemore power out of my engine. I do not run any power boxes or anything like that... YET! And with the more miles I put on it the better it runs. I now have 18k on the odo, and it gets better every day.
So give it some air and miles and I'll bet it will come around.
One more thing.. Before this trip. The best mileage I could get was 14mpg just day to day driving. After the "big pull", I now get 16mpg! Go figure. I don't know why, but my mpg is much better. On one solo trip to Chicago and back last week, I got 17.8 running empty. That has never happened before!

So to all who believe their 03 is down on power. Give it some time. Give it some miles. And give it some AIR, and I think you will be amazed. That's been my experience.