Looking for direction on replacing 2006 H3 Engine
 

I read the many different threads regarding engine replacements and still come away confused - 3.5 vs 3.7, upgrade to 08' - PCM TCM?, conversion kits, etc. :confused: And, I really appreciate those on this forum as it has been so helpful in the past on many levels, especially the failed heating resister - you folks are AWESOME - Thanks - but, I am in serious an emergent need of your kindness once again.

Last night my son called to inform me that the engine light came on and the H3 stopped running. With 213K on this well cared for beauty, Taps is now being played in honor of her service :( and Amazing Grace to follow for giving so much fun, life, and respect :).

With that said, she still looks beautiful, just needs a new heart (engine). Please help! I am searching sites/yards etc for used engines - just want to make certain if I do bring her back, she has a ticker worth my time/money.

Thanks again!

Wow 213k miles and it goes? 1st post here but this thread def makes me want to re think what im about to buy. Thanks I guess and good luck

first,just to be accurate regards the "resistor". in the vast majority of trouble cases it was the connector,NOT the res,even though some people stubbornly changed the resistor,(then the conn) i try hard to recall a case where it was the res.

engine; from what ive read,here, moving to a 3.7 complicates things.to keep it simple,(a simple eng swap?), id look for a 3.5 rebuild.if you missed the head issue on the first , you may not on a used one. what mileage did you get. i heard the 3.5 did better.
my max in 3.7 is 20 on trips.
long block engine$,??,$5000
low miles 08,h3,?, $20000+

You can find used engines on ebay anywhere from 7-1200, another 800-1000 for install. 213k is not a bad mileage count for the size and weight of the vehicle, but that all depends on maintenance.

I have built a lot of motors and I have been looking for a stroker kit for the i-5, I haven't been able to find one yet, but what I would do instead of putting a stock motor back in is balance the assembly, bore it .030, have the head ported and polished and install some larger valves.

you wont find anyone but a professional engine design team messing with major mechanical mods on this complex piece of machinery. balance? id like to know someone who could just explain the design concept behind the two,,,count em ,, two balance shafts already in the i5, yeah,in sync every 11 revolutions just for starters. figger that. an average guy dont need advice about mods that aint never gonna happen.

there is nothing complex about the I5 motor. We have had to balance many 4.3 v-6's with and without a balance shaft. I did one that was 33grams out of balance. When a motor is balanced, the reciprocating assembly is balanced that includes the flywheel, front damper each pistons weighs the same, the rods etc. There is some horsepower to be gained and it makes the engine more efficent and durable.

I am no professional, but I would replace the motor with same "new" motor. I have a quote for my replacement (3.5 going into a 2006) which is $7500 canadian, installed with 3 year 100k warranty on parts and labor. Ive seen used engines between 1500-3000.

I'm not sure what the cause was but the "engine light came on and it stopped running", could indicate a lot if things, like no oil and or no coolant and it just saved itself from total ruin, by going into limp mode or total shut down.
A better description of it's failure would have to be had but unless it's locked up why pronounce it dead? Have a compression check done.
Unless you broke a crank or camshaft or what drives it, (which can probably be repaired) it could be electronics failure.
If you just want to stick an engine in to get going or don't have the knowledge or tools I can understand why you would not rebuild it.
I'm old enough to have been around when precision balancing a factory engine was a big deal and often made enough difference to require stiffer valve springs to keep them from "floating" because the revolving parts were so much more efficient. Heck we balanced the crank shafts, drive shafts and all the pistons and machined down the fly wheel for less rotating weight and balanced it to the point you could sit still tap the throttle and blip it close to red line and it would fall back to idle quickly. Not your grandpa's pickup and lousy in traffic. You had to keep your foot in it and GOOOOO
I think current engines use technology to achieve the best of all of this applied to the final product.
Yea if I was rebuilding an I-5 boring to achieve a 3.7 (which I think is probably what GM did) and reprogramming the PCM to take advantage of more displacement would be the way to go.
Sounds like you should get a professional opinion of WHY it is not running before writing it off.
New bearings, boring and honing the cylinders, new rings and a valve job could come up with about what a crate motor would be.
I don't think larger valves is going to happen!
Attachment 14238
Maybe it's not that simple anymore, I have rebuilt about 20 engines and because your in there anyway why not improve things?
Starting over with someone else's problems may not be any better.
I think the I-5 is a sweet little motor but needs more displacement when your H3 reaches 6000 lbs!
I think my next rebuild hopefully waaay in the future will be my 5.3L.

Old school, signing off................

thats what i faced years ago when money was real tight and my van 302 at 144000 coasted to a stop with no oil pressure. it had been dropping and i fed it some 20/50 for awhile. when i added up the parts plus machine shop work, a long block was an ez decision,my time not figured in. btw,one rod wiggled when i pulled the pan,but more were to follow im sure.

hunner,i can tell you are capable but face it,there arent many around who are ,or want to do a rebuild. not me fur sure! i would trust a good,known builder.
lets face it,the i5 is not my dads straight 6 chevy,not an ez build for anyone.
and no,the valves aint growing any bigger.