Hey everyone -

I have an 07 H3 lux with the I5 with auto. Everything has been stock to date.

Took the rig to the dealer (I purchase it there) in California for an exhaust leak (very small tick sound) when cold. Within less than 30 seconds the exhaust tick would go away and stay that way till the next days "cold start". I also have had on occasion to find the rig would put itself into 4 high when put into drive or reverse (happened to the wife 3 times) and after reading up on this, the (encoder motor) on the transfer case needed possible attention

I expected the dealer to say "that's normal" to the exhaust leak and keep driving it but as the story gets better. I never noticed a "check engine light" and the H3 always started and ran great

Dealership called and said that they pulled up a "check engine" code for # 5 cylinder misfire and had already started the head removal for a "New" complete head. Upon further inspection the dealer also found the cams to be worn oddly and also provided complete new cams and cam parts.

Now for the questions::::::

Is the new head, cams valves etc. truly "New and revised" ????
I have done several forum searches and see a reference to better "valves or seats".

Soooooo - with all of the great info I've received here, who knows this answer ?

Will this "fix" (with revised parts) be permanent and last for years or is it destined to happen with the I5 motor ?

p.s. --- never asked this dealer to step up the way they have. They handled everything without ever giving me (the customer) any grief. Oh and they put a new encoder motor in even though they found no reason for the problem

 

Havent heard of 07s having the head issue. Perhaps the engine parts stock was running low when they built your motor and "found" some extra stock out back?

 

I would guess that your 07 had an early build date and the 3.7 hadn't been totally refined... The new head "should" be the best of the best as far as heads go that are available for the I5...

 

I have owned me Hummer for about 2 weeks. Now I'm getting a cylinder 5 misfire code. My H3 has about 96,000 miles on it. I am switching them out today and see what happens.