My H3 with about 17,000 miles started to idle rough a while back. Otherwise it seems to run good. No real loss in power. I'm wondering if this means I have head/cylinder problems? It seems to get worse if I use certain electrical items when idling, like power windows or step on the brake etc.. Just wondering if anyone has any insight on this. Mine was one of the earlier 2006's built.

 

I think everyone that has had teh head/valve issue also had a check engine light for a misfire. The rough idle condition you are having will get worse when elctrical items are used just cause taking more juice will lower the rpms slightly and cause more rough idle. I would check the obvious first, air filter, type of fuel, normal stuff like that.

 

Replace the MAF and see if that fixes it..

 

the MAF should send a code as well I think Dennis? also it's kinda expensive to replace one to to see if it fixes it. I would definately bring it to the dealer for that.

 

As previously stated in several posts, my "check engine light" did NOT ever come on (thru a week of driving it after it began to idle ROUGHLY)....I only knew it was an engine misfire code thru OnStar's informing me.

 

thats strange because the only way onstar would know of a misfire is if the engine sent a code, which also should have tripped the light at the same time. thats very strange...not saying your a lier...just saying thats odd that the light didn't go off.

 

Honest engine ( being PC LOL) hun, the light never came on. In fact it happened 3/4 of the way to the mountains immediately afterwe had just done a refuel, so we thought "OK, maybe we got bad gas." The rough idling continued thru another couple tanks and us thinking maybe we should put some additive in it???? Coincidentally when we made our destination, it happened to also be onthe same date my monthly OnStar email report comes...it containedan "emissions problem" message and to call Onstar for which I did. They then ran a diagnostic test and said all they could tell me is the diagnostic "showed an engine misfire at some point and to proceed to my nearest dealer." Of course no dealer to proceed to in the mountains, so we chanced it until we got home and I took it into the dealer the next day...got the dreaded head news. OK, so does my check engine light not work properly?????

 

try cutting some random wires under the hood, that should tell you if the light works or not. i'd start with a plug wire, or something coming off the injection or air intake, just not the battery cable . . . .[8D]

 

LOL OK SB...are ya just messin with me too? [sm=laughat.gif]And just what do I do then after I cut these wires?? (besides tape em back together LOL) [sm=noooo.gif]

 

now that i think about it, it would probably be easier to just cut the serpentine belt. then you can take it to the dealer and have it replaced under warranty, as well as whatever else breaks once you do that. but, you'll at least know if the check engine light works . . . .[8D]