The check engine light went off twice. I am seeing a Cylinder 5 misfire. I was going to swap out the plug with a new one to at least eliminate that from the equation. Anyone know where plug 5 is located? I hope its just a plug but my guess is a head/valve issue that others complained about in other threads. I just hit 50k on my 08.

 

Only some 06's were PRONE to that issue. Anything is possible. Plug or coil packs are your first 2 checks.

 

i have a 06 and im just having that problem, same as you are, misfiring on cylinder 5, hoping its just plugs and a quick an cheap swap, i hit 65k tho....

quick question an im sure ill sound dumb but the cylinders are numbered from front to back? i dont have a chilton manual or anything to help me know, jus making sure tho....

 

65K Seems to be the magic number... I'm in the software business and the conspiracy theorist in me can't help but think there are misdeeds afoot.

My 06 starting occassionally idling rough recently. I'll have to take it in soon for a code check and see what's up with that... Could a misfiring cylinder cause rough idle?

 

if they program this stuff in at the factory you'd think they would at least use a random number generator. u know, somewhere between 43000 and ,say 68000 miles.
with lots of memory and complex machine code,well ,anything that can be conceived,can be,,,stuck in a subroutine,huh! whats next?

 

I just got this exact problem fixed, (after 3 trips to the dealership and about $900 later!) the dealership kept telling me they fixed it and then a day or two later it would always come back! so finnaly they told me that the coil needed to be replaced but it was gonna cost $110 just for the coil from the dealership. so i called oriley auto parts and they said they didnt have one for the h3 so i found out that they put the same coil pack on several different trucks, ie. trailblazer or colorado. i got one from a trail blazer, replaced it, runs like a champ! hope this helps. and if you do take it to the dealership i would not listen to them when they tell you that they can clean the throttle body, replace the cam sensor, or relearn the computer to fix your prob.

 

Oh yea i forgot to add that buying the part from the auto parts store will save you $70-$80

 

I had that on my '07 for a few days. Went to the parts store, bought a couple bottles of techron. Code was gone on the way home from the parts store (maybe they cleared it when they pulled the code?). After running a couple bottles of techron through it and switching to a top tear gas station instead of the convenient one on the corner the cel hasn't come back.

Worth a try.

 

I AM SO PROUD OF MY HUMMER THAT I BROUGHT IT TO THE DEALER JUST TO GET A NEW CYLINDER HEAD AT 21K. ITS BEEN SO GOOD TO ME WITH SUCH LOW MILES THAT I TOOK IT TO ITS FAVORITE PLACE AND THATS THE HUMMER DEALER. WELL DO NOT WASTE YOUR TIME WITH TESTING AND PRAYING AND STAYING POSITIVE, JUST GO HEAD AND BRING IT IN FOR A NEW HEAD JOB. IT WILL RUN BETTER AFTER YOU GIVE GM SOME MORE OF YOUR MONEY.
I WILL GIVE EVERYONE A GLIMPSE OF THE ENGINEERING BLUNDER OF A ENGINE P03005 MOVE THE COIL, MOVE THE PLUG, DRIVE SEE IF IT GOES AWAY...NO, OK COMPRESSION TEST WOW LESS THE 50 PERCENT COMPRESSION HUMM..ERRR
NOW DRIVE TO DEALER AND BRING A BUCKET OF SAND YULL NEED IT TO STICK YOUR HEAD IN AFTER YOU HAVE TO PAY THE BILL..
ONE OTHER THING GO AHEAD AND CALL THE OUT SOURCED GM COSTUMER SERVICE AND BUST THERE CHOPS..THEY NEED TO HEAR FROM US AMERICAN CAR PEOPLE. THEY MIGHT PUT THERE FOOT IN THERE MOUTH AND TELL YOU ITS NORMAL WARE AND TARE, I LOVED HEARING THAT. MY REPLY TO THEM WAS" I HOPE THAT NO ONE ELSE HEARS THAT" LOL.
ALL THOSE WHO THINK ITS A NICE TRUCK AND A GOOD DEAL PLEASE BE ADVISED THAT GM DOES NOT STICK NEXT TO THERE PRODUCT AND REALLY DONT CARE ABOUT YOU. ITS ONLY NORMAL WARE AND TARE TO PRACTICABLY REBUILD A ENGINE AT 21K..
HAVE A NICE DAY GM AND I HOPE WE DONT BAIL YOU GUYS OUT AGAIN WHEN YOUR CRAPY A** COMPANY GOES UNDER BECAUSE YOUR PRODUCT IS INFERIOR TO WHATEVER ELSE IT OUT THERE,
" SHOULD HAVE BOUGHT A FORD"

 

still can!!