I notice that the threads on cylinder head problems just sort of end in 2012. What's that mean? Everyone has there's fixed? All possible information is available through search? My understanding was that the problem was in early 2006. But I see peeps with bed heads in 07 -09 as well. Mine is a late 06. My VIN is above the at risk number. My head was replaced at 4,000 miles. Now I'm at 97,000.(im the new owner). Do I still have head issues to worry about? Is it that the issue was solded in the 3500i but 3700i had new problems?

 

From a post of mine back in 2009, I think this will help you understand "the head issue":

"The S/Ns affected is any 2006 H3 lower than 287591 .... the first one started with 100,001, your truck build date will be Nov. 06 or earlier. Not all have the problem, but some could. The head issue affected not only the I5, 4s and 6s were subject to the same issues. Call GM with your vin# and build date (from the sticker in the driver's door jam) and ask.

Just in case you're gonna say, wow they didn't even build that many 3s? The VINs are assigned at the same Shreveport plant building Colorados and Canyons. Their VIN sequence unit #s are mixed in and subject to the same TSB re: the head/valve issue.

The recall and extended warranty was for very early 2006s, those with the 3.5L L52 Motors built before March 31, 2006. That is not to say some 3.7L LLRs have never had a valve or head issue. All the Atlas motors built since 4/1/06 have the new hardened valve seats."

Like oh so many people that fly by a forum searching for what they think is their problem, and jump in with the old I have that exact problem.... the head issue caused by the lack of hardened valve seats was corrected permanently. If you have an issue with your head or valve train, it is a different problem. Many things can mimic symptoms, like:
bad valve spring, cracked valve spring or weak one, bad valve, bad valve seal, blown head gasket, missing valve retainer, cracked head.....

Just like any 4 stroke motor can have a valve or head issue, any Atlas motor might develop head or valve issue, but they will not all be the same.

The other reason you see so much chatter about Atlas motor head issues, is GM was lazy and decided it was easier to throw a new head assembly at the problem than have a tech at the stealerships actually diagnose the culprit and fix it.

 

Thank you for replying. Btw, your thread was the first I read before buying my H3. Great info. I'm still perplexed as to why the head on my truck was replaced at 4,000 miles as my vin is a higher number than the affected vins. GM told me mine was not part of any recall except the hood/grill recall. So it would seem mine had hardened valve seats but was replaced under warranty if the first few months of life. How does any head go bad in 4000 miles?

 

That is the crazy thing, instead of a tear down and simple fix for some problems (example: broken valve spring), they just had a cost ineffective approach of replacing the entire head assembly. There have also been folks that have had their replacement head assembly also replaced again at a later date? No wonder they went bankrupt.

I would not worry, drive and enjoy.

 

It just could have been a bad one, anything man made can and will fail. I bought a brand new 79 chevy LUV pickup and the motor blew on my way home from the dealership.
Crap happens.

 

Great so I'm going to pretend that my Hummer is no different than any of the other GM trucks I've owned in the last decade and assume I can just drive without constantly worrying. because the ore I read, the more I felt that I bought this thing rite when the head was about to blow.