Since the other deisel discussion has turned to DPF malfunctions, I'll post another related question. I have had some strange experiences lately with my 2008 Duramax. I took a video of the dash with it acting up on Friday. See the youtube video:

https://www.youtube.com/watch?v=MPa4BRNb0Yw

It's done this to me about 5 times now. Of those 5 times, this was only the second time that it gave me the "clean exhaust filter" message. That message popped up after it started this surging behavior when I tried t to pull away from a stop sign. 10 mph is about all the quicker it will go. If I push harder on the throttle, it just surges more violently. It only does this when it's time for a DPF regen, but it doesn't do it every time. The only cure I have found is to shut the ignition off and restart. If it's still not right, shut it off again and repeat until it runs right. On Friday, it was about the 5th time I restarted it that the truck immediately went into regen and it ran fine at that point.

The two times that it did this and gave me the "clean exhaust filter" message, it also threw a MAF sensor code (P0101) and went into limp mode (this video was taken after clearing the code and exiting limp mode). The other times, it never gave me any codes and the CEL never came on.

Anyone ever seen this before? I've only had the truck since October and it has 115,000 miles on it. All stock, no mods. This truck is my daily driver and it'll go for weeks with multiple regens, before this problem shows up again.

I posted about this on a diesel truck forum about a month ago, before I had video of the malfunction. The most useful response I got there was a suggestion to clean the MAF sensor. I doubted that would do anything, since more than half the incidences have not included the MAF sensor code. I cleaned it anyway, and the problem persists.

2008 here also. Mine did this once, right after i had put on the programmer. It was like in limp mode. I could clear DTC's and all and still the issue. Got it home and unhooked both batteries for about half hour. After that no issues. Programmer has been on it since. I do drive mine a lot short distances, wawa coffee gotta have it, so from time to time i get the clean exhaust filter msg, so we just usually make a detour and get some heat in the chamber. If im towing or going on a long trip, it usually re-gens about once per tank on its own no issues.

Has the truck had any EGR problems. Sounds exactly the same like in the big trucks i service on calls when the EGR takes a dump (Pulsing) PO101 MAF could also be relative to EGR issues.Has a PO401 ever surfaced (Prior) that you know of?

This message has been edited. Last edited by: TD3550,

quote:

Originally posted by TD3550:
Has the truck had any EGR problems. Sounds exactly the same like in the big trucks i service on calls when the EGR takes a dump (Pulsing) PO101 MAF could also be relative to EGR issues.

If the problem is EGR-related, I can't say.

I have a friend with a diesel truck performance shop nearby, and I've had him plug into the computer 3 times now. Every time, he says everything looks ok, including the EGR. But that's not to say that the problem is EGR and it's just not acting up when he's plugged in. The only thing he did say was that, based on the sensor readings, he thinks the DPF is plugged and needs to be replaced. He did a manual regen on it about 6 weeks ago and it's acted up twice since then.

Any suggestions for how to diagnose the EGR when it's not surging like this?

Factory or aftermarket air filter?

Does his software show any flow rate or back pressure data on the EGR or the DPF. Most of the restrictions on the big trucks with the software i use will show this data. I have one friend that pulled the manifold off and did the clean out with replacing the EGR. Not to say that is your issue.

quote:

Originally posted by TD3550:
Does his software show any flow rate or back pressure data on the EGR or the DPF. Most of the restrictions on the big trucks with the software i use will show this data. I have one friend that pulled the manifold off and did the clean out with replacing the EGR. Not to say that is your issue.

I can't say what all his software actually shows. But these are questions I can ask!

The air filter is an OEM replacement. I know that K&N filters can mess with the MAF sensor, if the computer isn't calibrated for it.

Make sure the filter is installed correct. I have seen them be off a little and cause strange stuff. Also check for air leaks between MAF and engine.

One quick question. Does his software show any warranted calibration updates that are needed?

That's another question I'll have to ask. I appreciate the help!

It's hard to diagnose a problem you can't reproduce on command, especially when it doesn't throw a code.

How do you know when it regens?

I have a friend that works for the county and they have to fix these trucks from time to time. He told me that the variable vane turbos get sooted-up and there is a sensor that tells the ECM the position of something, not sure if it the waste gate, whatever......... He said you can sometimes clean it, but usually a new turbo is needed. Again, this comes from not getting them under load and getting the turbo spinning fast enough......

Seems like this diesel thing is good when it works right, and a real PITA when it doesn't. Gas engines don't have these issues, but they don't have the power either.

quote:

Originally posted by Mike Beck:
How do you know when it regens?

I drove the truck for over a month before I ever noticed a regen, in process. After a bit of research and investigation, the only sure way I can tell that a regen is in process is the idle speed. It idles at ~650 RPM under normal conditions and ~800 RPM during a regen. The second indicator is the oil change indicator. The oil quality number drops 2-3% over a few miles, during a regen, and rarely changes at all between regens.

With my programmer on the dash i can see the EGT climb, also the higher idle. As far as not getting heat in the system when riding around, i guess its good i have a heavy foot.

Ok, I have heard the idle speed go up before on it's own, so now I know why it happened.

The more I read here the more I know my 2007 is a keeper......

quote:

Originally posted by J178RED:
The more I read here the more I know my 2007 is a keeper......

That's what I was told, but didn't find any that either weren't high mileage and/or unmolested. One friend has one and he won't sell it for nuttin!

I do have a 1999 3500 Dually 4wd that I just use to move trailers around with. It is a BBC and pretty simple setup. I won't sell that truck for that reason, too easy to get parts for and fix.

My buddy wants to put a Cummins in it for me. He put one in his 79 Camaro, what a blast that was! With all this DEF and emissions BS on the new diesels, the Cummins in my old truck is looking better and better!

My 2007 Duramax Classic will stay in my driveway until it rots out or blows up. I don’t even use it to tow anymore very often. Pickups are just way to useful not to have. I have not owned or driven a people car in probably 35 years.

wierd things happen when batteries are going bad. are they new old or been tested lately?