# Duramax Problem



## Pelican (Nov 16, 2001)

My buddy's Chevy Duramax has an rpm surge at idle, so much so that when stopped in "drive", the truck lurches if you're not standing on the brake pedal. He's had it back to the dealer, was told "They do that". It doesn't seem very safe to me or my buddy, and makes maneuvering in tight quarters interesting to say the least.

Has anyone else experienced this problem, or know of a fix?


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## BWhite (Sep 30, 2002)

*unbelieveable answer*

what a poor service department there ....There are no more good mechanics or service writers . a service writers job is to blame anything and everything on everything but the problem and ASE only means 4th grade reading skills


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## Mike 97 SS (Aug 11, 2002)

I dont know anything about diesels, but i would guess that they have an Idle Speed Control motor like other regular gas engines and maybe it has gone bad? I see it happen alot of Ford vehicles where the little Idle Control Solenoid goes bad and the idle surges up and down, up and down. First thing i would get checked if it even has one on there. Mike


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## GM-GUY (Nov 1, 2002)

They do not do that - I have one.
2001 K2500HD with the Allison.

Most likely, the ECM & TCM need to be reflashed. There are computer upgrades that address this concern. This must be done in two steps with the Tech II, and both the ECM & TCM must be done - the tranny and engine talk you know.....

The fuel pump (high pressure) is a remote chance.


When I first got my truck, fine - perfect. Then the dealer upgrades to a beta version of ECM/TCM - LURCH CITY. New updates, last fall I think, all is well and good again.

There are bulletins about this.


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## 90plow (Dec 22, 2001)

My dads truck did this and he brought it back ended up being soemthing with the Bosch injection they had to replace it. I think the surging stopped after that I'll double check though.


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## Pelican (Nov 16, 2001)

Thanks, GM-Guy, I'll relay this info to my friend.

I'm not impressed with this dealer's service manager, I bought my wife an Impala there last fall and have had it back twice for brake problems. Each time he tried to blame the problems on improper servicing on my part. I don't think I'll be back.


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## cat320 (Aug 25, 2000)

I'd be calling chevy up and complaining to them of the type of service that he is giving to you


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## GM-GUY (Nov 1, 2002)

Duramax diesels are tough, most won't work on becuase they are clueless. Find a GMC dealer, and how many Dmax's sold since 2001 and what they have worked on. That's how I found my service center.

Some dealers (most around here) are awful. I have been through ten (10) chevy dealers. 
They all had one or more of the following:
a) It's normal
b) We can fix it (but never did, cancelled 4 appt's - 'too busy')
c) We will 'decline' to work on this because another dealer has worked on it - different issue.
d) Just plain stupid, rude, arrogant.

I have found the best, GM service center now - VERY HAPPY. The GMC dealer in Hudson, MA (Tucks).


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## GM-GUY (Nov 1, 2002)

Oops, hit the button too quick.

I did call the 800 GM line 6 months ago I guess. I can now get warranty work done at the GMC dealer - no questions asked. A magic little case number I started about the dealer service.


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## John DiMartino (Jan 22, 2000)

Pelican,a lot of the duramaxes do have a lopey idle ,its a common complaint/problem .He does not want it reflashed,the reflash will kill his power above 2500 RPM,and once reflashed you cannot go back,ever to the old flash.My cousins 02 had the lope/surge until it had about 6K on it.My buddies did it intermittently.What ever he does do not let them flash it,have him do dome reading on the dleselpage,lots of horror storys there about the ones that got reflashed.It will probably go away,but at least its documented if it doesnt.


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## Pelican (Nov 16, 2001)

His truck currently has 35,000 miles on it, I don't know when this condition started. I don't think he's a big net surfer, but I'll pass it on. Do you have an address?


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## John DiMartino (Jan 22, 2000)

Pelican, have him surf over to http://forum.62-65-dieselpage.com/cgi-bin/ultimatebb.cgi. I know that some problems were fuel related,as in injection pumps.There is a lot of info on there.My cousins hasnt loped in 5 months now. JD


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## GM-GUY (Nov 1, 2002)

JD:
I had the loss of power with the beta set of upgrades done without my consent. Apparently some dealers consider ref-flashes S.O.P. The new set (last spring on futher eval), fixed it and power is back.

The one odd thing is throttle progression is off from original. I have to put more foot to get the same RPM/Speed. I didn't loose MPG, just the pedal is different (drive by wire=no cable).

But you are correct, make darn sure that you can't live with what it's doing. If the upgrade messing something up, no way back until a new upgrade comes out.

I now have tape and a note over the Tech II hookup "Don't even think about it"


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## Pelican (Nov 16, 2001)

Talked to my buddy yesterday and his truck's in the shop. It seems they've found the problem, the fuel transfer pump and the injection pump were not designed to work together. The wayt he described it the fuel pump didn't have enough pressure at idle to overcome the fuel return. I'll keep you all posted on the repairs made, it's due back tomorrow.


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## Pickering snow removal (Jan 8, 2003)

*gm dealers*

Darn read your post pelican, That said let me state some facts here , One there is a pcm reflash to improve idle on the duramax.

John fyi you can reflash back to org software , we use a software format called tis 2000 if the driveabilty tech understands the tis system then he knows how to back flash.

Bwhite please tell me your refer your dealer in your area or do you mean that "ase automotive service excellence" is a title given to all of us techs and means " what did you say can only read at a fourth grade level "

sorry but i guess you hit a grand slam homer with me I have worked for a gm dealer for a total of 20yrs I will be honest to tell you that not every truck dealer has a diesel tech many dealers were forced to send a tech to school to learn much is true for dodge, with the cummins and ford with the power stroke,

Has it looks by pelicans last post the dealer is working to solve the problem has we have had some with transfer pump match problems,

WE has techs never quit learning every year we have to work on and diag problems on vechs with new designs and new technolgy
all of which is paid on a flat rate system !!!

What i recommend to everyone reading this post if you have a duramax ask your dealer is there a tech on staff that works directly with diesels it my be in your best intrest to use a dealer that does remember just because they sell them doesnt ness mean they have a fully trained dura tech

This applys to dodge and fords has well many dodge owners prefer using the cummins dealer and ford owners the international dealer. I know has people read this there saying hes working at a gm dealer owns all fords something fishy right 
wrong, just like fords and the fact they use a real front end not ifs
on the sd,s just my pref i have a great relationship with my ford dealer even though i am capable of repairing any make when i go to the ford dealer i dont go in with a ego or try and diag my problem iam under warr and i let them do there thing if it seems out of line i might say something but they have treated me well

Last the reason i started my company is because of all the above said it is getting harder and harder to make it has a tech the pay does not benifit the amount of time and exper for example gm, ford, chrys do not pay us to road test your vech for intermitt problems under warr, We do our best i know there is bad dealers i know there are bad techs, bad service writers, this i know but BWhite ASE was designed to help weed those out


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## sno-mover (Jan 12, 2002)

This is a little off tipic, but I read that the duramax uses alumnium heads. Is this true, and if so why?


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## cat320 (Aug 25, 2000)

Ask that same question on the diesel page and they will rip your head off.Not sure whay they wouls put aluminum on top of cast iron?


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## John DiMartino (Jan 22, 2000)

The Duramax uses aluminum heads to save weight.This hasnt been a problem so far,theyseem to be good engines,we have bunch of them around here,and a few in my family as well.BTW theu are great cold starters too,its been -13 here a few nights ago,and -7 last night.My cousin still hasnt plugged his in,it fires right up,on remote start easliy.


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## sno-mover (Jan 12, 2002)

Thanks for clearing that up for me. I may be wrong but I cant see them holding up that well, they are two completly different kinds of meatels, that are constintaly going too be expanding and contracting at different rates.


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## Pelican (Nov 16, 2001)

John, how do you know when the glow plug cycle has ended with the remote, or do you just guess?


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## John DiMartino (Jan 22, 2000)

The glow plug light is wired into the remote start unit,the remote start unit will not engage the starter until the light goes out.It works just as good on a PSD and Cummins too.I have one in my Ram as well. The units are made by Crimestopper. John


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## John DiMartino (Jan 22, 2000)

Sno mover,they have been using dissimilar metals on car/truck engiens for over 20 yrs now.I do agree that in time the head gasket will be more likely to fail than if it had iron heads.All I know is the ones in my family,and that friends own get run hard,none of them has had any issues at all.A few of the trucks are getting ready to turn 100K,and they are not easy highway miles either.


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## joed (Dec 26, 2001)

I think you might have a problem with your fuel injectors or fuel pump. My 92 Ford diesel did the same thing your Duramax was doing. I had to replace the injectors and after some fiddling around with the rpms, all went well. The only other thing I can think of is that you may have air getting into your fuel lines.


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## Pelican (Nov 16, 2001)

I brought this thread back for an update. The surging problem was corrected, but my buddy had so many other intermittent problems with sensor inputs that Chevy bought the truck back and gave him a new '03 with the Duramax. So far, no problems, but it has that butt ugly grill!


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## cat320 (Aug 25, 2000)

He should of tried to get a GMC a little better looking than the Chevy.


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## Brickman (Jun 17, 2002)

> _Originally posted by sno-mover _
> *Thanks for clearing that up for me. I may be wrong but I cant see them holding up that well, they are two completly different kinds of meatels, that are constintaly going too be expanding and contracting at different rates. *


I agree, and that is why I have no use for that set up.


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## Brickman (Jun 17, 2002)

> _Originally posted by John DiMartino _
> *The Duramax uses aluminum heads to save weight.This hasnt been a problem so far,theyseem to be good engines,we have bunch of them around here,and a few in my family as well.BTW theu are great cold starters too,its been -13 here a few nights ago,and -7 last night.My cousin still hasnt plugged his in,it fires right up,on remote start easliy. *


Hey John I have not had my PSD plugged in during the winter for over a year. And have had absolutely no starting problems.


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## Brickman (Jun 17, 2002)

> _Originally posted by John DiMartino _
> *Sno mover,they have been using dissimilar metals on car/truck engiens for over 20 yrs now.I do agree that in time the head gasket will be more likely to fail than if it had iron heads.All I know is the ones in my family,and that friends own get run hard,none of them has had any issues at all.A few of the trucks are getting ready to turn 100K,and they are not easy highway miles either. *


What the difference in my opinion is that the diesels have much higher compression than the gassers do. You rarely heard about head gasket problems on gassers with aluminum heads/cast blocks.


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## Plowtoy (Dec 15, 2001)

Hi there!
A guy i had plowing for me last year had the same problem talked about in this topic (idle surge). It ended up that the injection pump was bad, The dealer replaced it and its been good since!!!. 
I left my dealer ship job last october (2002) as a ASE certified master mechanic. Let me tell you that when i left, the duramax was one of the reasons!!!! I faught and faught with them to get problems fixed (most major was a coolant leak, that finely got fixed after i quit at another dealership) Come to find out that isuzu (who manufactures those engines) will only let duramax certified techs work on those engines!!!!! We at the dealer did not know that. Anyway watch out for those allisen 5speeds (not as tough as gm thought)


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## 90plow (Dec 22, 2001)

My dads D-max just went in for sencond set of injectors and injector pump at 52,000. They said to prevent this keep the fuel filter changed. I dont know why its such a problem maybe because the injectors are real fine?? They said change it every three oil changes or so. We shall see.....
Eric


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## wxmn6 (May 23, 2001)

I have read in other forum related to Duramax diesel, and have seen alot of threads related to fuel filter. Some of them said that they added a second fuel filter and don't have a problem.


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## 90plow (Dec 22, 2001)

Wxmn do you have any information on this setup on how they are doing it or how I would go about getting this installed. My dad is interested for his truck.
Thanks
Eric


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## wxmn6 (May 23, 2001)

Eric, you have a PM. :waving:


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