3.5L vs 3.7L?
 

Hi everyone. I'm currently in the market for an H3. I noticed there was a different engine in the 06 year. Does anyone have any experiences, comments, suggestions, etc about the differences between these two engines? Thank you.

RE: 3.5L vs 3.7L?
 

It's a no-brainer. The 3.7 has more torque and horsepower. The H3 is still underpowered.

RE: 3.5L vs 3.7L?
 

Ditto...
I have a 3,7L and although still a bit underpowered, the difference with the couple of 3,5L I triedis small yet REAL. you can really feel it.

RE: 3.5L vs 3.7L?
 

just get an Alpha:D

RE: 3.5L vs 3.7L?
 

Thanks for the replies and info so far. I did noticed the HP and Torque increases with the 3.7L. However, I could easily gain that with some aftermarket additions while saving money on a later model H3.

What I'm mainly concerned with is the durability of each engine? Was there a problem (other than less power) with the 3.5L? Any reason why not to buy it?

RE: 3.5L vs 3.7L?
 

The 3.6 had some serious head issues. This was corrected with the 3.7

RE: 3.5L vs 3.7L?
 

Ah, ok. Thats what I wanted to hear. I assumed there would be more issues with the 3.5L other than power. It always seems the first year a new model comes out there are issues with many things...including the engine. Same thing with the early year LS1's.

Do you know what was wrong with the heads?

RE: 3.5L vs 3.7L?
 

As I recall the heads would warp. "07 3.7 is the safe way to go.

RE: 3.5L vs 3.7L?
 

I would get he 07 3.7 before the 06 3.5. The problem on the heads was the valve seats were soft causing misfire issues. This was a bunch of early h3's before vin break 68287591 that could have this problem. There is a definite power difference (feel) between the 3.5 and the 3.7. Steve

RE: 3.5L vs 3.7L?
 

New member here.

I have an 06 ADV with 3.5L that I purchased new in September 2005 and have 42000 miles on it now. I did have the head issue that was taken care of under warranty. The head issue ususally shows up early on (within 20K miles) and should be taken care of under warranty. The head issue did not leave me stranded or cause obvious performace issues (in my case), only a check engine light. I have had an 07/08 with the 3.7L as a loaner and it does feel as though it has a little more go. I don't think there will be a problem with how long the 3.5L will last as it's been used by GM for a while in other applications. I plan on keeping mine for at least 10 more years so I guess I'll find out.