GM Warranty/Aftermarket Parts [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: GM Warranty/Aftermarket Parts


thorco69
03-04-2004, 12:01 PM
Hi Guys,


I initially placed a topic under Voided Warranty/Hypertech but I am doing a new one so more people will see it. What GM initially thought was a bad PCM due to Hypertech, is no longer an issue. My truck has now been diagnosed with extra turbo boost issues causing my problem (according to GM). I am now at a GM dealer and with a Service Manager who is a good guy and going above and beyond to help me. GM had them do more than 15 different tests to try and find the cause but could not.


They sent out a tech engineer, and all he can say is that the truck must be put back to completely stock in order to find the problem. He states that in some cases, exhaust systems, larger tires, air systems, are causing various egr, and other sensor problems. They feel that by putting it back to stock, it will fix my problems, but if not, they can at lease eliminate those issues once and for all. Luckily I kept the original wheels and tires, though my truck will look funny for a while, having a 6 inch lift, with the original tires instead of 315's. I did not keep my old exhaust when I put in a Banks system, but the service manager found a shop in San Diego who kept a system from when they converted another vehicle.


So today, the an original exhaust is being put on and I am taking the original tires to the dealer. Luckily I only put in a K&N filter and not a complete system.


Here is the good thing, my attorney got GM to agree that if all this is done, and the truck still has the same problem, that they will reimburse me for any cost to restore back to original.


From talking to GM, they are going to begin to take a very hard stance on any Duramax/Allison problems when there has been any kind of modification. All beware that you won't simply be able to unplug, your juice, or get the pcm back to stock, you may well have to replace your exhaust and other things back to stock, when you take your vehicle in for any kind of problem. Edited by: thorco69

duramaxdiesel
03-04-2004, 12:23 PM
It could be worse I guess. At least they didn't say you had to take off your lift kit. I still don't see how an exhaust modification and K&N could make your truck have these problems. Hope it all gets worked out though. Nick

dmaxalliTech
03-04-2004, 12:27 PM
Have they updated the programming for the overboost codes on your truck? I see its an 01 and I would hope they have done that. Anytime intke and exhaust mods have been done, you change the way the air enters and exits the engine, the programming in the puter is set up for stock components that look for set values. You improve it and it could confuse things as it see's more then it should. Usually its not a problem, but I think thats why they are going to these extremes.

duramaxdiesel
03-04-2004, 01:47 PM
And that my friends is why I'm not a mechanichttp://www.dieselplace.com/forum/smileys/Big Smile.gif Learn something new everyday.

thorco69
03-04-2004, 05:42 PM
When I went to the dealer today the service manager told me that found something that may well be the culprit. Even while running with no load the speed at which the fuel pressure regulator is flutuating way beyond specs, and the same gm tech expert stated that may well be the problem. Gm has authorized putting in a new fuel pressure regulator to see if it operates within specs. I was told that if it supplies too much fuel, or sends fuel to fast, the turbos may well be over-boosted and the engine is supposed to shut before meltdown (their words).


Of course they still wanted the stock tires and wheels and the exhaust done, but thru the grace of a good service manager, we will try the regulator without changing anything else, so as to pinpoint the problem..


And yes, the computer has been reprogrammed. ThanksEdited by: thorco69

dmaxalliTech
03-04-2004, 05:56 PM
are you having an idle surge? Lumpy idle?

thorco69
03-04-2004, 09:48 PM
dmaxallitech,


No I am not having any idle problems, just when under a load towing my 10,000 trailer not my 5,000 trailer the engine shuts down because of a now diagnosed over boost situation, then after a few seconds the engine just begins to run again.

Heartbeat Hauler
03-04-2004, 10:04 PM
You'ld think the waste gate would prevent an overboost condition. That is of course unless the wastegate or the electronics that detect this condition is faulty.....Hmmmmhttp://www.dieselplace.com/forum/smileys/Geek.gif


JP