HUH????? there IS a flaw...gm knows there was a bad batch of heads and are now casting the heads differently. I guess you can believe what you like, but the bad heads that where put on some of the h3's is a FACT that gm is correcting.

 

OK, I respect your opinion, but if THERE is a flaw some COLORADO/CANYON should have the same problem since they use the same engine.
do you think there is a way to find THAT out?

 

If I may internationally mediate here

These engines are in fact the same used in the Colorado and Canyon..very true..But as all car manufactures do, they sub out certain parts of the engine to be made out of house and I'm sure to the lowest bidder..The Heads are not a pure common componet on any engine and the H3 has had some (minor) design spec changes to accomodate the H3...The supplier of these heads is where the fault lies..But the basic BLOCK is still the same.

 

What exactly happens when they go bad??
A soft head and valve may be causing the problem but what IS the problem?

 

Thanks Dennis, you beat me to it

 

You've seen people mention it being a valve guide problem...I've heard and believe it to be maybe SOFT VALVE SEATS..For one thing if it was a VALVE GUIDE, it would only puff smoke on start-up after an overnight set, or after all day long in the parking lot..But that would be the size of the problem with Valve Guides (BTW--GM engines are notorious for this problem)...On the other hand, if it were the Valve SEATS, it would cause; loss of compression, and maybe even some backfiring and loss of power, along with a very rough idle....As has been the case of everyone that has seen this problem.

I'm like Mike..If it happens it happens..They will now fix it for sure, as the future of the H3 name rides on it.

 

I think it is the valve seats, I just always type vavle guides out of habit, my tahoe had to have that job done twice in 4 years

 

OK, OK, I surrender

May I suggest, with all due respect to ImportKiller, to throw away the bloody engine and replace it with a good 8 cyl. 5.7 HEMI jeep engine ........ built by MERCEDES

 

Is it just me, or is this the same problem cars had back in the '70's when they took the lead out of gas? Seems to me you had to pull the heads and have hard valve seats put in along with new valves because the old ones used the lead deposites as a cushion for the valves to seat on. If this is the case, I wonder if you could con your dealership into sending the head in to get ported and polished and cc'd since they have it out. Obviously you would have to pay for the extra work, but it would be a lot cheaper at that point then any other time. Then all you have to do is wait for a lower end problem to have the lower end balanced and blueprinted. All that would be left is to get a cam ground for more torque that will still pass emission and throw in a chip and exhaust. Then it would run like a raped ape.

 

linus, good idea...costly but would be an awesome ride
I think the problem is similiar to the 70's when the switch was made from leaded to unleaded, I wasn't into cars other than my tonka trucks back then but a few older mechanic friends that I bowl with said they all dealt with this problem back then.

JM, don't know what to make of your post exactly but a new hemi in the h3 would be fine by me.