View Full Version : D/A mind of it's own
The RPM's will jump about 300 by it self when you are trying to go slow like in a parking lot going slowly between cars. I have almost been in a couple of accidents because of this. From what GM's power train div says the PCM is programed so when it senses that the engine is going to stall it will rev the engine 300 RPM's. GM tells me that I own the truck and I have to live with it!! I won't let anyone else drive it in this condition. Being a 1 ton it is not covered by the local lemon law ( it is over 9000 lbs). The BBB only goes to 10,000lbs the truck is rated at 11,300lbs.
My uncle has an 02 Dodge, manual transmission that does the same thing and he hates when trying to crawl along hunting roads in the winter.
Yeah, I test drove a F**d a couple years ago and it was a stick, which does the same thing.
I have spoken to several duramax/allison owners and some of them have the same problem but just ignore it. I feel that if GM disclosed thsi I would not have purchased the truck. I have owned 2 dodge/cummins still have the last one no problems. Put a superchip and KN in it I get 16-17 MPG towing a 7000lbs trailer no matter what speed I go. 22mpg empty at any speed under 80mph. Also the cruise control will only hold within 8mph when towing GM says this is normal for fuel economy.
Clyde,
Sounds like you need to see another dealer who can work with you.
I have the D/A and do not have that problem at slow speed or any speed.
Which Cummins do you have that gets 22mpg at any speed? I have a neighbor who has the old 12 valve and a newer 24 valve. Neither will get over 17-18 mpg on their best day.
The max I have seen my cruise very is 5 mph and that was down hill, my D/A seems to hold better than any of my gas trucks.
Try a different dealership who can work with you.
smartfix
08-18-2003, 15:32
Hello all
We Do Not have this jumping at low speed .. We go up many parking lots real slow and everything is fine
2003 Duramax ..
From steve
Does it have EGR and a catalyst???
BlueOx03
08-18-2003, 16:10
Mine doesn't do that either and idle run it everyday. I have the soot returner and burner. Kennedy, are you thinking that it may be trying to keep the emissions stuff warm or keep the gasses moving? I also wonder if this could just be smoothed out with programming. If the high idle can be changed, shouldn
Lone Eagle
08-18-2003, 16:28
As the man said: Take it to another dealer. Some of the 01s would surge 50 RPM and the cruise should not drop more than 3 to 3 1/2 MPH before downshifting. Later! Lone Eagle
Thinking maybe the EGR/throttle gizmo is getting sticky and/or lost or confused.
I have heard that the 6 speeds can do some odd "hanging up" and flaring making a guy look like a rookie driver in parking lots etc...
I have been in the auto/truck/motorcycle/automotive machine shop business over 40 years. My strong background is high performance machine work. I currently have owned a motorcycle dealership for 25years. I have general machine shop/dyno for my sons mx bikes /a flow bench and a bunch of computer programs I work with on the 2 strokes. Two friends who use to work for me own the old machine shop I use to run. They build some of the best engines in the northeast. The dealer is a friend and I have know the service people for a long time. I have spoken to several duramax tech's and they tell me up here in the northeast they are having all sorts of problems. On my truck when the computer thinks the engine is going to stall (drop below a set rpm) it is programed to speed it up 300 rpm's. GM tells me and I have confirmed it that all late duramax's are programed this way. Under the right conditions turning the wheel,hitting the brakes and with the AC kicking in I can catch the engine just right when I back out of the throttle very gently you can feel the rpm's drop under the norm and that is when the computer takes over. It has done it to me 5 times. The first time within 10 days of ownership. GM had one case of a 3500 high cube van that did it in reverse and the truck kept slamming into loading docks. What bugs me is that the power train div knows this problem is there but they will not address it. As for the crusie control when the truck is loaded/ slidein camper and the 18' trailer, set it at 70mph it will drop to 65 then kick down and go to 72-73 then lock up and drop down to the preset of 70. What I have to do is when I see a grade just over ride the pedal then when it drops 1 or 2 mph it will kick down then the cruise will take over. I get 8 mpg when towing this combination. When I first picked up the truck in April It vibrated so bad I coul not go over 65 or so. GM said this was due to the way the truck was tied down during deliver to the dealer and it would go away in1500 to 2000 miles. Well they didn't know what to say when I stated I had over 2000 miles on it. The dealer balanced and road forced tested the 6 tires 5 were over a reading of 80 so they replaced them, they are going to do the spare when I get it back in. All I get from GM is lip service. The dealer has gone to bat for me but there hands are tied, because I have caused such a stink at GM.
a64pilot
08-19-2003, 07:12
Clyde,
What year is your truck? What your describing sure sounds like my truck before it was reflashed for idle flair and shift business during cruise, of course mine is an early 01 and I think the 02's and on didn't display those problems. Darned if it dosen't sound familar though.
Mike Fultz
08-19-2003, 11:06
Clyde, I have noticed the same issue with my '03 2500HD D/A (6500 miles). So far it has only happened when the engine is cool, and only in the parking lot or my driveway. The first time it happened it caught me off guard and I thought I was going to plow through the garage door. I think the 300 RPM jump sounds about right. Each time it has happened, I have come off the throttle and then back on and off again just to get a little momentum. I will have to watch closely and see if I can find any other condistions that exist when it happens.
Mike Fultz
Mike, mine does the exact same thing as you describe.
When I leave work I make a sharp turn and go up a hill to leave the parking lot. I let off the fuel to make the turn, then it surges. This is the only place it has happened, always when the engine is cold.
I believe this has been discussed before.
http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=006157#000000
I had a customer come into my dealership today he has a year old duramax/6 speed 44000 miles. His truck has done this same thing since new and he has learned to live with it. This isn't right!!!!!! GM can fix this problem if they want but it is cheaper not to and if they loose a few customers so what, they sell 800,000 trucks a year.I know I worked for a GMC dealer once, we handle everything from pickups to class 8's plus the famous GMC motorhome. I was the service and parts director and full certified on all aspects of the trade. I also managed the truck leasing operation about 500 pieces. They didn't care then and they don't now. I have registered complaint with the NSHTA, FTC and Ralph Naders group. I was instrumental in the lemon law cover motorcycle in NH and I will see that it goes from 9,000 lbs to 12,000 lbs during the next legislative session. I also drafted and had passed the same lemon law and dealer bill of rights that pertain to titled vehicles which now covers OHRV's GM might have won this battle but in NH they will lose the war in the long run.
I used the wrong acronum for National Highway Traffic Safety Administration, sorry! (NHTSA)
Dave Lewis
08-19-2003, 20:49
Same problem with mine. Happened when I was turning around in a driveway with the air on. It just about put me through the garage door of the in-laws (wouldn't that have been nice). It's kind of scary to think what would happen if somebody was standing near the truck when it decided to drive itself.
I would like to know how many other people are having teh same problems? Thanks
dmaxalliTech
08-22-2003, 19:33
Clyde, mine does it.. Left turn, most noticable, a real rough idle flare. acts as if the cam is WAY to big to be streetable... I havent found a cure yet.
dmaxalliTech
08-22-2003, 19:37
Clyde, mine does it.. Left turn, most noticable, a real rough idle flare. acts as if the cam is WAY to big to be streetable... I havent found a cure yet.
chuntag95
08-22-2003, 20:50
Mine too and the reflash did not solve it. Mine normally does it whenever I am close to another expensive vehicle like a Porsche or something. :eek: :rolleyes:
About half the duramax owners that I have come in contact with have similar problems with the throttle. It seems that when they go back to the dealers they are told it is normal that they have to live with it. I find this answer unacceptable! When you spend between 40 and 50 grand for a vehicle one would like to think that it would perform better and that the manufactuer would be more helpful am I wrong?
Mike Fultz
08-28-2003, 13:28
.... another note about this.... Three weeks ago I bought my daughter a 2003 Pontiac Sunfire. I went to park the car in the garage and just rolling along at 1 MPH I turn the wheel hard left to position it in the garage. Sure enough I got the 300 RPM increase on that car just like the truck. O.k. so my only two GM vehicles have this "feature"..... Oh well, I guess I have to get used to it.
Mike Fultz
If I put my tranny in neutral going down hill,say starting from a stop, as speed increases engine rpm also increases.I think this is programed in because the brake boost pressure is provided by the power steering pump.Your problem may not be related to this but thought I would throw it in anyways as a general observation.
WillowCreekStable
08-30-2003, 14:34
This isn't just GM's, nor is it a new problem. My first fuel injected car was a 1988 Mustang. Turn the wheel to lock at idle speed, the added PS pump load would drag the RPM's down a bit and it would blip the thottle to compensate. Yup the dealer said 'normal'. My truck does it too, usually when cold.
It seems that I am not the only one have these problems , has anyone come up with a fix??
FirstDiesel
09-15-2003, 17:37
I usually get one 200-300 rpm surge in the morning when the truck is cold after I back out of the driveway and put it into drive.
Dave_WB3FYV
09-16-2003, 09:13
The 01's had it bad.
Do a search for 'lopey idle' and see if any of that discussion fits your problem. Replacing injectors and/or fuel pressure regulator fixed all that took their trucks in.
In my case, running a fuel additive for a while seems to have minimized the surging, and it's getting smoother as it gets older. It was never a 300 prm surge, in fact, it was hard to see the tach needle swing at all - but it COULD be the same cause n effect.
http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=004674#000011
I have 8365 mi. on my 03 GMC truck, and so far no problems at all. After reading these posts I got in my truck and rode around the yard to see if the "surge" acured, luckily it hasn't. smile.gif I agree GM should do something to fix the problem.
After looking at the posts again, it looks as though the problem trucks so far as posts read are Chevy LT's. I didn't see anyone with a GMC having the problem. Sounds wierd just the Chevy would have it and not the GMC, but it is possible. Just a thought. :confused:
Since this post has started I have not had one surge, maybe it is an Allison learning thing. About 14,000 miles on the clock.
Does this surge happen with the manual transmissions?
From what I can surmise the 300rpm jump happens to both auto and standard models. I know of poeple with plain jane trucks, with the duramax that have this problem, it is frustrating. I wish I could get it fixed as I don't trust the truck. I am at the end of my rope with this truck. I wish I could get enough owners together and the NHTSA to make GM issue a recall and either buy them back or fix them.
Clyde, you must have something that is out of whack.
When mine surged, it was very slight, nothing to be concerned about. Since it doesn't do it anymore, I don't think I can help.
How many dealers have you been to?
The dealer is a friend they went all the way to the power train division and they were told there were no cases therefore they had no cure for my problem. They would not open a case either on my truck. From what I can tell they are in denial because it is such a wide spread problem
I guess I am disappointed I was told that my problem could be solved by this web site. All I have found out is that I am not the only one with this problem. Over all the truck isn't that bad, I just don't have any confidence in the truck. After reading some of the problems other people are having I am discouraged. I have notified the NHTSA and the FTC, the next agency left the CPSC. They just had a recall enacted on Dean Kamen,s Segway,s because they will fall over when the battery goes dead, even though there is a low battery light. Bt this analogy all vehicles should be recalled beacuse if you run out fuel in the middle of an intersate someone might get hurt! I'll keep everyone posted. Thanks for the input from everyone. Clyde
Dr_Crane
10-04-2003, 09:18
Clyde; My truck has done this since day one but I now know how to avoid it so it doesn't bother me. I just assumed this was a characteristic of the "fly by wire" electronic throttle. My background is in heavy trucks and equipment so I don't consider this a major problem. ( try running something with an air throttle!) Heavy trucks do essentially the same thing. I have yet to drive or operate anything that in my opinion has been completely flawless. I didn't realize this problem could be so potentially dangerous so I would encourage you to pursue goal to have this problem addressed.
Dave_WB3FYV
10-06-2003, 09:36
Clyde,
I'm not sure where you are going with this thread. Are you, per chance, a lawyer?
Your last post seemed to start bashing this forum because WE couldn't solve your problem. Several members have posted replies asking questions and offering suggestions but I don't see where you have provided any more information to help us help you. All I can tell is you have a 1 ton.
So, does your truck have a catlyst? an EGR system? What year is it? Have you tried running a fuel additive to help lubricate the injectors? Have you tried another dealer? What happens with a new fuel filter installed? Is your carpet stuck under the accelerator pedal? What else have you done other than taking the truck back to your dealer friend and notifying the NHTSA, the FTC, the BBB, Ralph Nader and the CPSC?
Many, many problems have been solved by members of this forum. The amount of information available is mind bogglying, but no one here is a mind reader. Answer a few questions, try a few things and let's see if we can get you fixed. Every problem, quirk, unusual condition or bad mood that my truck had was resolved by discussion here, but it wasn't a one way street.
Sorry if I seem a little short, but I truly want to see a resolution to this problem.
My fuel injected Harley would buck and stutter while rolling at idle in parking lots - until I made the fuel/air mixture a little more rich. Dealer originally told me "that's just the way it is", I didn't agree.
With very few exceptions, every problem has a solution - often more than one. Let's see what we can.
I am not a lawyer can't stand them. If you read my posts i gave a history of who I am and my experience in the field. The problem with the truck is a programing issue, the power train division admitted this to a couple of dealers that I know. At this point in time the factory refuses to address this problem why it is anybody's guess. The truck runs great has plenty of power once off idle. This problem only happens once in a while when the computer senses that the engine is going to stall. In other words when the rpm,s fall below a certain value then the computer speeds the engine up 300 rpm's. GM says it is programed this way, and I am out of luck that I have to live with it. GM claims that I have the latest program in the cpm. It appears not to be an injector or fuel problem. The way to make it happen is to start the vehicle and have the air on then turn the wheel like in a tight parking spot where you are lightly on and off the throttle and brakes, this drags the rpm's down then the cpm takes over. The engine will literly go up and down 300 rpm's across a parking lot until you touch the brake pedal. Pretty simple no mystery, I had it happen one day and some friends watch it as I let it go for a couple of hundred feet.
I guess I amfrustrated with my truck, because I haven't been able to resolve the problems. Because I pushed so hard Chevy has told me tough. I can sell or trade the truck and lose $9-10,000. The three local dealers all have several low mileage duramax's on their lots that were purchased at the GM auctions, they paid between #34 & 35,000 for these 3500 series trucks, so much for resale value. You would think when there is a safety issue that Chevy would care, there answer is we have a large legal staff for just this reason. How would any of us feel if we injuried someone because of a malfunction? I guess I have to make a decision pretty soon, either trade or spend some money and fight Chevy.
flhrciblueice
10-18-2003, 20:35
Originally posted by Dave_WB3FYV:
My fuel injected Harley would buck and stutter while rolling at idle in parking lots - until I made the fuel/air mixture a little more rich. Dealer originally told me "that's just the way it is", I didn't agree.
With very few exceptions, every problem has a solution - often more than one. Let's see what we can. Dave,
I had the same problem with my '01 Harley fuelie and did the same thing to fix it. I told the mechanics at the dealership and now they have been doing the same thing for any customers that complain about the problem.
DieselDo'er
10-19-2003, 11:44
Clyde
My Dmax has done the same when comming to a stop. The AC was not running nor was I making a turn. The truck has done this when warm (driven over 20 miles) or when cold. When warm I was at a intersection and glad I had not stopped very close to the person in front of me. I try to make sure my foot is firmly planted on the brake when I come to a stop but don't always remember, it does this very spuratically(sp), some other times was when leaving to go to or come home from work. Have not said anything to a dealer since no code has been set and I have not seen anybody else bring up this problem before and figured I would get the same runaround as you. I will make a copy of this post to show the dealer and see what happens since this is happening to more than just me. I also have the reflash for lopey idle and the cruise control doing the yo-yo thing with the tranny. Unlike some I wish I could get it to do it with the air on and turning the wheel?
Hope this helps you to build your dispute aginst them.
Brian
Aggie '91
10-19-2003, 19:34
The idle surge is not just on GM vehicles. I have a 2000 Dodge Dakota quad cab (4 door) 4X4 with the 4.7L gas & manual 5sp xmsn. That truck does the 3 - 500 rpm surge when it thinks it will die.
It has done this since it was new. Try backing a trailer into an uphill tight spot!! ( My normal trailer shed) I have learned to live with it, but it is a real pain. as I ride the clutch to back the trailer in . . .all I can smell it the clutch burning.
The ONLY way around that in the little Dak is to go into 4WD low range & let low gears & torque work for me instead of smoking my clutch.
I guess everything with computer controled fuel injection does this. I have not noticed this on my d-max, but maby I was already used to it from the dakota smile.gif
There are two big chevy dealers and one GMC dealer in my area, the GMC dealer has 5 duramax's down with between 60-70,000 miles on them for injectors and they are on back order. The chevy dealer has 7 duramax'd down for various reason's Does anyone know if this is going to be the norm when we get some milage on these things?
Diesels Forever
10-24-2003, 05:58
I had the same exact problem with my 01. Dealer put a new injector pump on it and it was fine after. But developed a noise see Injector Noise post.
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