H3 3.7 Engine Options
 

I have a 2008 H3 that was told that the engine was bad. I plan on getting it checked out to make sure but was wondering The most cost effective path to take based upon my situation. 1. The transmission was replaced about 2k miles ago. 2. I plan on keeping the H3 for at least 3-5 more years. It currently has 144k on the current engine. Everything on it functions as it should. AC, Heat, Stereo System, Lights, windows, seats etc. Trying to determine if I should look at rebuilding the engine, or get a salvaged engine, or get a remanufactured engine, or get a new engine. Also, I noticed that the H3 3.7 and the Chevy Colo and GMC Canyon seem to be the same engine but not sure if you go that route if it is a simple replacement or I need to watch out for some gotcha’s if I go the salvaged engine route. Trying to minimize cost on this

First, why does it need a new engine.

I would first make certain the "engine was bad" because I do not blindly believe what any Jamoke says about this or that. Most of them will go many more miles than you have.

Any 3.7L I5 from any of the 2007-2010 H3s, H3T, Colly or Canyon would all be fine replacements.

A salvage engine is a roll of the dice some times, rebuilds can be great or not so much depending upon the source. A re-manufactured/re-conditioned motor can be a great way to go, but again you have to know the source.

Good luck.

Thank you for the advice. I was able to locate a reputable mechanic and going to take it in to have a look. I was able to get it started today and it idled well until it warmed up and then started to idle rough and die. It will start back up tthough. Also a noticeable knock starts at around 1400 rpm and it gets pretty back at 2000 rpm. The idle reminds me of a timing chain issue but the knocking has me concerned. 175k miles on it and it was ran low on oil so I think the engine replacement might in play. Do you know if the canyon engine is a plug and play or will I need to have some mods to make it fit.

All of the I5 3.7L LLR motors will bolt in, most will run as is without further work. To do it right I would consider having the PCM tuned to the motor vin #.

should be plug and play but if there are any changes in brackets or mounts or harness you will have your originals on hand. same goes for dipsticks.

Forgot to mention.... the 2006 and 2007 H3s have different Throttle Bodies than the 2008+ motors so plan on using your existing TB.

Another missed oppertunity for GM
 

t's a shame GM didn't use the 4.3 V6 (old technology though) or the 3.6 which would have been much lighter was built on new tech and both powerful with good mileage numbers. Either would have been far superior to the 5 banger, I think thtat would have really boosted the long term H3 values (much like the 5.3 did)

Old post. But I will add.
Not only different throttle bodies, but also different electronics. And different cylinder heads. There are two types of 3.7 and they are not interchangeable. You have to be careful with this. 2007 and 2008-2010.

Good point, Diesel.