My 2006 H3 has 90,000 miles .... no problems ever until......

Check engine light off and on
Rough Idle

Cleaned fuel injector system
Replaced Cam Sensor
Plugs

Code keeps saying cylinder 5 misfire
Now I'm told I need to replace entire head gasket and quite possibly the engine
Come on Hummer folks give me some feedback...I have been reading bad reports about the production of the 2006 H3

 

Welcome.

Your thread was MOVED from the New Member area because it asks that no technical questions be asked in that section.

Have you cleaned both your MAF snsor and Throttle Body???? Basic fuel injected engine maintenance about every 30-50K miles that you do not read about in the owner's manual.

 

Hi
Before I'd go pulling the engine I'd start with....
* new oem spark plugs (ac delco)
* new c.o.p. on each cylinder
* new intake gasket or very least make certain it's tight
* new oem injectors or equivalent
Jmho

Chris.


Whole lot cheaper than a new engine or gasket.

 

And yes I saw the spark plugs were replaced. I just don't count on the 1st try. I'd swap 4 & 5 at the very least. Here is a link to some of the part numbers you'll be seeking.

https://sites.google.com/site/happyh...helpful-data-1

 

tammy~you don't need a new engine, maybe just a remanufactured head & gasket. A simple search will give you more info on the misfire code P0305, whoever changed your plugs are giving you the basics of swapping the coils and plugs like #4 cylinder for #5. They already told you if the TB and MAF sensor were dirty. While eliminating the basic stuff consider your VIN# knowing if your last say 8 digits are less than 68287591 your within the widely known "head issue" range involving the Shreveport plant Atlas motors. The misfire problem can occur at "any" mileage but a GMC regional service manager has said all those engines installed before they addressed the problem 4/06 will eventually fail at some point and it's more likely to be the cylinder #5 soft valve seats that leak first. You can drive the vehicle for over a year with occasional misfires until it becomes unsafe to drive, especially at low idle say accelerating out of intersections. Sure the problem could be a bad spring or dirty injector but the percentage of documented cases point to the head defect, this is the age of component replacement and GM's got a specially remanufactured head kit package already prepared for your poor Atlas motor that one would expect to last well over 100k.

Assuming the person who told you what you needed was a qualified mechanic, the bottomline; part# 19168846 the remanufactured head $869.00, part# 88984219 the gasket kit $224.70, 15 bolts (2) 11519038 (12) 11609709 (1) 11519306 $97.30. The labor... anyone who enjoys 10 hours under the hood and dealing with the fun stuff like bolts broken off in the block, if not just find a Hummer tech but don't pay over a grand, you can always tip him afterwards cause nothing like a smooth running H3.