I had the same cylinder head issue on my 06 H3, 58,000 miles 2 months ago. Started giving P0302 Code. Changed plugs, coil pack, cleaned MAF & TB, etc..and double-checked before calling GM Goodwill Program provided from this site. GM directed me to a Cadillac Dealership in Chantilly, VA. #5 cylinder leak test revealed 50 percent leakage. Service Manager stepped up to the plate. Replaced with whole new improved cylinder head assembly at NO COST! Treated as under warranty and advised that there wasn't any need for the GM Program as they would take care of it themselves. Acknowledged 3.5 I5 head issue and was professional. Very pro-Hummer! 62,000 so far and no code, misfires, or problems.

 

Hello Folks,

This is my second post to this forum as a prospective H3 owner. I'm considering the purchase of a 2006 H3 with ~70k miles. Looks to be in good condition and was running well until yesterday when the Passlock system kicked in and prevented the engine from starting. That is being worked on now by the dealer. Assuming that issue is resolved, I will proceed with consideration of buying this H3. In researching the Passlock issue, I stumbled upon this thread and many others like it.

My question for this thread is assuming there are no current code thrown indicating there is a problem, is it worth paying $135 to the dealer to do a cylinder leak test (or other tests) to rule out this issue?

Independent of the PIP3935D issue, does anyone have general advice on what tests to have a dealer/mechanic perform to ensure the H3 has no current issues?

 

Welcome to the forums.

Here is your first problem, you are digging up OLD threads. Read the old dead stuff, do not necro post in them. https://www.hummerforums.com/forum/h...bumping-23221/

If you have a question, start a NEW thread.

To rule out if you have the 3.5L built before the switch to hardened valve seats, look at the serial number and ask the dealer for a vehicle history report to see if the head was already changed.

Look at this thread currently on the front page of the H3 board https://www.hummerforums.com/forum/h...-please-29740/

 

We also are having this issue with our 06 with 37k miles on it.
Could you please update me with what transpired and if you have the letter that was sent to you could you forward it to me to use with my dealership please. This is driving me crazy, my dealership says the chev canyon that runs the same engine, 3.5l is under recall but not the H3's. Stupid but what can you do?
Please advise and let me know
Thanks

 

Hey Flash
Could you send a copy of that letter to my email? I too am going through this issue, sure would help to have all the ammo to get this fixed. If you can, my email is:
ies@telus.net

Thanks

 

The person you are speaking to joined the forum for a single day over a year ago and hasn't been back since.

 

...and it's been over a year for Flash as well.

 

Well thanks for the update
Still going to go after GM/Chev about this. Called them here in Canada, they were reluctant to talk to me about this but used the knowledge gained here to prod them into opening up a "file". They then told me the only dealer in my area that can do a diagnosis to let them (GM) know if they will offer any assistance.

Will advise as this proceeds.

 

Maybe you should look up online and see if there are any recalls for what's happening to your hummy. That's really low miles for that to bar happening to it. I would tell them All or nothing. Bring up the word lemon.

 

Hello,
I have a the same problem, can you please send me that letter also?
my email address is thecigarguy23@gmail.com
Thanks so much