'03 Down on power?

[WillowCreekStable]

First of all let me introduce myself. I am the proud owner of a '02 Chev 2500HD LT Ext Cab. I've had it about two months now, and enjoy listening to it so much I didn't know what the radio sounded like until last week. Awesome truck!

My question concerns a friend's '03. This is his 3rd Duramax/Allison. It doesn't have the power of his 1st two trucks, which were identical to this one. I drove it back to back with mine and it feels like it's down 50 hp. With a relatively light trailer (maybe 3,500 lbs) it fades to 90 km going up a hill that the old trucks could climb at 100 km without downshifting.

Does the computer have a reduced power setting for a break in period? If so, how long? Do Canadian Duramax's have the egr system and can that be the problem? Any known problems with the '03's?

Appreciate any input...

[ 11-30-2002: Message edited by: WillowCreekStable ]</p>

[c5dura]

I heard the '03s were actually a bit stronger, generally speaking. Perhaps there is an issue with his, or it needs to be broken in a bit more?

[WillowCreekStable]

It doesn

[polaris800]

I have a new 2003 with 3000 miles on it. To date it feels the same as my 2001. One thing i have notice is that it smokes a lot more. How I can tell is that I even see the smoke in the day time. My 01 m=never did this not sure if I have a problem going on or not but I will continue to monitor it. The power feels all the same,

[DMaxCaptain]

Also have an '03 with 3000 miles. So far, everything (power, lack of smoke ...) seems the same as the '01 that I traded with the possible exception the DMax in the new truck seems to be just a bit louder from inside the cab.

[Duke]

I have an 03' Crew D/A. I had the exact truck 02'
model that I just traded. I too noticed my 03' feels like it is down on power by about 50HP, 100lbs of torque from the old one. I actually posted this a month ago or so.
I wanted to break the truck in before taking it back to the dealer to ensure it wasn't just tight. Took it in for service yesterday and just got a call from the dealer. They have been running diagnostics with GM factory and turns out they found the source of the problem. This is real interesting!
Turns out even though there is an actual cable from the pedal running to the fuel injection system, it is actually a "drive by wire system" in the truck. There is an electric impulse provided by the pedal that feeds the PCM(I'm guessing that is what it feeds)as well and it turns out the signal to the PCM is erratic and I am never actually sending a signal for full throttle. Wow!!!
They are still working on the exact component that is causing the problem but the good news is they have narrowed it down to the exact area. I think we may have just found the source of the problem for all these sluggish 03's. I tell you this is a weird problem. The truck runs fine, idles fine, and drives fine it is just lacking abit of power. If I would not have owned a previous model I would have never known there was a problem. I wonder how many first time owners are out there with 03's that have this problem that don't know!The truck still has more power than a P-Stroke or Dodge.

[conradv]

I'm a first time DMAX owner (2003) with 2500 miles and would be most impressed if I actually have more power than I do now. Keep us posted please, & Thanks!

[fredw]

duke: this makes sense, same problem i have compared to my 01,02, also mine is harder on fuel, will look into, thanks

[WillowCreekStable]

Duke - Thanks for the info. Did you have any problem convincing the dealer you had a problem, and is this condition easy to diagnose? I can hear the service writer saying they

[Duke]

The word from the dealer today is they have been trying various things that GM has suggested so far. They have shimmed and reshimmed the actuator and adjusted a few other things and the mechanic has noticed significant improvement. The issue is they can't really give it a solid road test because we are in the middle of a snowstorm. They are currently doing research to see if there is revision issues with these actuators. I am apparently the first case of this that GM Canada has had with the 2003's. So unfortunately I am the guinea pig on this one..........I hate that!!
Dealer has been awesome on this so far. I will pick it up tonight and drive it for the weekend and let them know on Monday.

Service Writer didn't have a problem on this at all. When I made the appointment I told them I had an 02' and now have an 03' and noticed this lack of power. He basically said if you had Duramax previously you know what they should be like. When I showed up the Diesel Tech and I went for a ride with him driving. He tried accelaration from 0, mid range and WOT. His comment was "I see what you mean, this is definitely the slowest one I have driven". We headed back to the shop and he told the service writer to write it up as "down on power everywhere". I have had no pushback at all really.

[Duke]

Met with the service tech today. They are now working with GM in the US. There is apparaently 5 trucks that GM knows about currently that are currently or have been in the shop for the same symptoms. They have put the rest on hold and have decided to use my truck as the test mule to find the cause of the issue. The tech emailed about 500 pages of data from the diagnostic port of my truck to GM for their analysis. They have suggested several modifications for the tech to try which he implemented through yesterday and today. I test drove the truck but in my opinion it is no better. He will relay that message back to GM. The factory seems keen to fix this issue. They have appararently called the tech atlest 5 times between yesterday and this morning for input on the success of the mods'. I will drive the truck this weekend and touch base with them Monday to see if they have more suggestions.

[SoCalDieselNewbie]

The 2003s are inconsistant on the Dyno and vary substantially from one another on the same dyno... on the same day...

A gentleman that I know has dynoed hundreds of powerjokes over many different production years... He says that they produced extremely consistant numbers from one truck to the next.

So while one guy thinks he has a slow 03, another thinks he has a fast 03.

[Duke]

Thats discouraging news. It's comments like that that make we wants my 02' back.

[conradv]

Yeah, but with your (Duke's) help, maybe we can find out WHY they are inconsistent. There has to be a solution. Just like there was a solution to the busy shifting, and the two piece driveshaft, and the loping idle, and etc, etc.......

[NickLeinonen]

" One thing i have notice is that it smokes a lot more. How I can tell is that I even see the smoke in the day time."

when the egr system is introduced, you will see more of this i believe.

diesel and egr don't mix in my book :(

[DieselDennis]

Well atleast GM seems intent on fixing this issue. I can see why they would want to. They don't want the Duramax getting a reputation as a sluggish truck with no power.

[Robert J Spence]

I test drove an 02 in july and have had my 03 since september.
I felt all along that this truck did'nt have near the power of the test drove 02.
I will wait to see how yours is resolved.
Thanks

[txguppy]

Ya think GM might have "detuned" the trucks for our neighbors to the north. tongue.gif tongue.gif

Just kidding!!

[fredw]

took mine into GM today, about power and fuel problem, also printed dukes problem and took it to them as well, it is still their, and they think the problem could be in the same area as his, will kept you updated

[NoMo]

Besides a "feeling" of reduced power, is there any other way to determine if one might have this problem? This is my first GM truck since a '63 gasser that I owned 20 years ago and it's my first ever diesel. I have no reference for power other than the V10 F350 I traded on this GMC. No doubt that my last truck would destroy the D/A in any kind of race. Haven't towed yet to see what that is like. Fuel economy seems OK at an average of 18mpg and there is no black smoke at all from the engine. :confused:

[conradv]

Well, I'm way up here in the pacific northwest (inland a bit) and I've been trying to find out where I can get my truck's HP & torque tested in the Spokane, Washington area. How much does it cost, & does anyone know where I would go? Searching on the internet hasn't led me to much.

[stutzismydog]

I have a 2003 D/A with 2000 miles so far with an overall average of 17.3 MPG and it runs like a raped ape. The weather in Calif. is still warm with 70 Dg. temps......so I don't know what to tell you. I hope that you find the problem.

[NoMo]

conradv-

If it's still in business, you might swing by the Hot Rod Cafe in Post Falls and ask some of the street-rodders that [used] to hang out there. I bet they know where & how much for dyno runs.

[chagburg]

I have a 2002 crewcab duramax allison & I thought it was low on power. I timed mine from 40 to 70 mph and it took 10 seconds. I drove a 2003 and timed it from 40 to 70 mph and it took 15 seconds. It seems there is a big difference from truck to truck on the power. I also wonder how many people out there are down on power and don't know it. I also had mine dynoed and it showed 17o rear wheel hp.

[Jomar]

My `02 has been in the body shop for the last 12 days and for the last 5 days I`ve been driving my son`s `03 which is just like mine. Mine runs real good but this `03 I believe runs a little better and it`s got less than 200 miles on it. It will burn rubber right on thru 2nd gear. No power loss there.


Jomar

[c5dura]

As far as a better method than 'seat of the pants' to meassure power, I would suggest getting an accelerometer such as the G-Tech. It is about $140 bucks and will allow you to accurately meassure things such as 0-60 and 1/4 mile times.

You should be able to get to 60 in less than 9 seconds if your truck isn't down on power.

For comparison, my '02 3500 crew cab long bed when it had 1400 miles, did it in 8.4 seconds (3 run average), which is pretty good considdering how heavy my truck is. And this was with 235-85's. Only mod was a K&N Aircharger.

Going to a dyno will typically cost you $70 a pop, so the G-Tech pays for itself pretty quickly.

[WillowCreekStable]

My friend sent his '03 to the dealer and they found the problem was with the electronic throttle. Easy to check, easy to fix. He got it back, used it yesterday to tow his horse trailer, and it now has all the awesome power we

[toms]

CONRADV

Call Shelly Automotive, They are in the Spokane Valley. I have had race cars dyno'd there, and if I remember correctl, They charge about $75.00 for three runs.

toms

[conradv]

thanks

[DMAX4LIFE]

What exactly did the dealer do to fix the problem. My dealer has been working on one for quite some time and has had no progress. Thanks

-Corey

[Duke]

The throttle position is sent via a electonic position sensor on the throttle pedal assembly. They changed mine and it improved the lack of power problem immensely. I still think my 02 was stronger but my 03' is much improved now.

[David Proske]

Chagburg wrote "I have a 2002 crewcab duramax allison & I thought it was low on power. I timed mine from 40 to 70 mph and it took 10 seconds. I drove a 2003 and timed it from 40 to 70 mph and it took 15 seconds"

My 2003 DA has 2400 miles on it and is bone stock. Today I did A 40-70 test with the AC on and trans in normal mode. Went from 40-70 in 8.2 secs.

[DURAMONSTER]

This could explain things. My brothers 02 is so dam fast. My 03 (with 2,000 miles on it) is so frigen slow. I was hoping it was the break in. But its just not getting any better. I was wishing For my 7.4 gasser back. But how am I to get the dealer to wast his time on it. Hand him a 20.

[DMAX4LIFE]

do you have a part number for the part replaced? Sorry I just want to have exactly what it is when I go to the dealer. Thanks

Corey

[britannic]

6000 miles has proven to be a big difference for our truck. Whilst it had power to start with, now there's a lot more on tap and it's very strong off the mark. Towing 7500 pounds isn't noticeable and I have to stay alert to keep to legal speeds.