Hummer H3: Can You Put A 3.7L I5 in a 2006 Year Model Year?

[Acer4LO]

Okay so I bought an very early model (GM mark of excellence badge is next to the H3 Badge instead of by the fender) Boulder Gray 2006 Hummer H3 that I have been meaning to fix. One of the things I need to do is replace the engine since it already has somewhere between 180k-200k. So my question is, can I easily replace the 3.5L with a 3.7L. Main reason why I want to do this is I found a engine with 73k miles for cheap because the owner just wants it out of his shop. Just wondering if the motor mounts are different, or am I going to have trouble getting the PCM and what not to communicate with it. Is it more trouble than its worth or an easy swap? Thanks!

 

[Jack_M]

I believe you can if it's a 3.7 from 2007 anything newer and it will have issues from what I understand.

 

[amrg]

You may get a better answer on the colorado forums!
Humvee sold his 3.7L to a guy who had to replace his 3.5L and as I recall the guy had issues with making the new engine work with the 3.5 stuff so he offered to sell Humvee the engine back!

Sent from my SM-G960F using Tapatalk

 

[atvspeed4]

24x reluctor engines from 2007 work direct bolt in with tune. 2008 and up can be swapped by following a how-to on the Colorado forums but it's not easy. We are buying a 2007 tomorrow from a guy that put our old 2006 3.5 in after his engine blew. It's running fine other than needing transmission rebuilt

 

[Acer4LO]

To clarify the owner is only selling the engine block. I would have to take off all the stuff all the old 3.5 like the alternator, etc and put it on the 3.7l. Am I going to run into problems there?

 

[atvspeed4]

If it is really only the block then yes you will have problems.

 

[Acer4LO]

I was thinking that too. Really only considering buying it because the owner has no use for it and needs it out of the shop asap because they are renovating the whole place. Would you guys know the value of it if I had to resell?

 

[rascole]

If it is really only the block then yesyou will have problems.

If it's just the block what problems will there be? From what I seen the blocks are nearly identical. I looked at an 08 from a Colorado in a junkyard and could not see any changes.