Hi:

I've got a 2008 H3 with 88,000 miles. It sort of idles rough in neutral, and there is some interior rattling noise I can't locate. Once in drive it 's better. It's done this since I bought the vehicle with 30,000 miles so I don't think it's a tune-up like problem.
Anyone else experience this?

Thanks,
Joe

 

MOVED from the FAQ section where it states: https://www.hummerforums.com/forum/h...section-19461/

If you have 80K some miles and never cleaned your Throttle Body & Maf, well know you have some searching out to do.

Use only Throttle Body cleaner for the TB, and MAF cleaner for the MAF. Might want to look at what is in the FAQ section and avoid posting there.

https://www.hummerforums.com/forum/h...what-do-33916/

 

I too had a very rough idle, almost seemed to wanna stall. Had the p0128 code. Replaced the thermostat, camshaft position sensor intake and exhaust, cleaned maf sensor and tbody. She runs much better but I need to check the crankshaft position sensor to see if the screens are still in place.

 

Clean your MAF and Throttle body... I did mine some days ago and for real the engine feels like new... I recovered a lot of power, the truck just goes faster and uses less pedal travel than before, better mileage, plus the engine runs really soft. Doing this is pretty simple and takes less than 30 minutes with the right tools. Check your air filter too.

 

Well, I cleaned the throttle body and MAF sensor, and changed the air filter. Vehicle runs like a champ...but now the engine light stays on. Anyone know how to fix this?

 

Have someone scan the code. If it's another issue or else you'll know it, but sometimes the EL stays on after a fix and needs to be reset.