AustinB

Hey guys im currently trying to figure out what is causing the misfire issue on a 2006 2500HD. Ive done a lot of things to try and figure it out but still have not been able to locate the problem. Trust me ive been searching lol

The truck started with a P0300, as I watch the misfire counter, cyl 1 is the only consistantly missing cylinder. I will sometimes pick up a few misses on other cylinders but nothing hard enough to pursue. So ive tried to isolate the problem with what ive done so far...

Swapped coil packs, wires, and injectors with cyl 3 (one at a time of course) new AC plug, injector drop test, spark output is the same as it is on cyl 3, checked extensively for an intake leak with brake clean and a smoke machine,exhaust is not restricted, Cam signal looks good, Ive had both cam and crank sensors out and they are fine, Ive done multiple crank relearns with out any change, Compression test 155 on cyl 1, had the valve cover off no broke valve spring, rocker arm action while cranking looks normal... the only thing i havent done is a leak down test but i dont think this will yeild me any different results... but im gonna probably end up doing one tomorrow

Still just a misfire on cyl 1 at and idle, when you bring it off idle, the truck will smooth out, but when hauling a load such as a boat, the misfire is pretty clear

Any other ideas? Im thinking internal engine failure.... lifter or cam...

gregs323

i had similar issues last summer and it ended up being a bad converter

1FastBrick

iTrader: (17)

Have you checked the wiring to the injectors and coils???

Have you tried running injector cleaner or engine oil additives???

Were are you located???

What are you using for a scan tool???

GmJackson53

Could be a issue in the harness... Not likely... But it seems like u have knocked
Out the obvious, besides an internal issue..

AustinB

Yes, Yes, Indiana, and a Solus Pro


We decided that it was probably a cam/lifter failure, GM even has a TSB on that year 6.0

pmgm

iTrader: (5)

What are you going to do? New cam and lifters? Stock or upgrade? I might be in the same boat..

Thanks

AustinB

Yep cam and lifters. It was a customers vehicle so he his deciding on the repair

stranger ranger

I would like to see this tsb they have out on this year 6.0

DrHoho02

I am having the same issue on my 06 Tahoe 5.3l. Is the same, number 1 cylinder and mine also shows a p0172 code. I thought I was missing something and the garage I use cannot find anything also. Let me know if you find out what the cause is.

pmgm

iTrader: (5)

You guys using a stock replacement cam and lifters? If not what are you replacing it with?

Thanks