Problems with DPF at 120,000 miles

[EdSpaek]

Team

Need some help

We have several of the 2008 Silverados with the LMM engine and recently on a couple of the trucks we are having issues with the trucks referencing the exhaust filter as requiring cleaning or reduced speed warnings. These trucks are maintained regularly and use top quality fuel with Stanadyne additives. The dealer on one of the trucks so far has replaced the exhaust pressure sensor, the mass air flow sensor, and is now thinking we need to replace the DPF filter and two temp sensors

The most recent code noted was P2453

From the internet posts this appears to be a new common problem that GM is not sure of the proper fix yet.

We did not expect issues with the DPF system at such low mileage

Any thoughts

[Kennedy]

While many are doing the "test pipe" and ECM programming, some are under closer scrutiny and need to live with these crappy devices. That said, about the best I can suggest is have one of the DPF's removed and serviced/cleaned to see if this fixes the issue.

[Kennedy]

Ed,

What percentage of biodiesel are these trucks running on? I know Il is pretty strongly behind the bio fuels and at one time I thought B11 was popular due to some sort of mandate or incentive.

[ceide4489]

Ive been told previously that it isnt uncommon to replace DPF at 100000 kiles so maybe its that time.

Would like to know what one costs if you do need to replace.

Might be the kick needed to do a delete

[EdSpaek]

Thanks guys for the replys

We use fuels that state at the pumps they may contain between 5 -20% bio diesel, seems these days all the pumps say this

Always hope it is closer to the 5% but you never know

[Kennedy]

Disclaimer: Sample of one, pure casual observation, and NO control for comparison.

I pulled the injectors on one of my 3 cylinder Yanmar engines in my compact tractor (Deere) to do some performance work. This machine had run a pretty good bit of B20-ish. I found a pretty healthy buildup of soft carbon on the tips. I tend to believe that bio leaves more combustion deposits contrary to what is claimed.

There are places that can split your DPF, clean thoroughly, and reassemble as a serviceable unit so if you are tied to it this is what I would suggest you try. Otherwise try a DPF "test" pipe and Offroad ECM for running at the track. ;)

[richp]

Hi,

This would seem to be an area for our Customer Service friends to look into.

The prevalance of blends up to 20% bio diesel is increasing. Many of us are finding pure diesel harder to get. That is particularly true in the Midwest, where the politics of bio fuels drives some of the market choices.

Is there anything GM can do to assist owners of this kind of system if problems develop well in advance of the otherwise expected life of the device?

Just asking...

[More Power]

GM approved the LML (2011+) trucks to use B20. The prior LMM trucks were approved for B5. This is due to cylinder washing because of the way the fuel systems introduce the extra fuel into the exhaust systems during an active regeneration of the DPF.

I haven't heard of bio affecting the injectors or DPF otherwise. Surely GM thoroughly tested bio before making their recommendations.

Jim