21st Feb 2015, 23:35

Just purchased an 06 Hummer H3, and I'm having cylinder 5 misfire and rough idle. I'm in for a class action law suit! Please advise.

3rd Mar 2015, 03:21

I too have a Hummer 2006 H3. Please fill me in on the class action at justinpena37@gmail.com


22nd Mar 2015, 17:25

OK, the same, but a little different.

'06 H3 bought new for 32k from a dealer. Never off road, all in town commute and/or highway, currently 125,000 miles.

In 2008, approx 25k miles, cam position sensor failed. Rough to no idle, easy repair, 1 hour, a $30 part.

In 2010, approx 60K miles, the water pump failed, and when it does, the clutch fan assembly "falls out" into the shroud. Instant stop, summer, 110 degree, mid town Phoenix AZ. Ouch! Not a difficult fix though, 3 hours, standard tools - $100 parts and coolant.

Power steering reservoir leak, O-ring between tank and pump.

Coolant Leak: Known issue with the radiator upper housing and body interference. New radiators have a slant to avoid metal to plastic contact. Old radiators can be spaced slightly to avoid.

And now for the dreaded P0300. Yes at about 90,000 miles we noticed a slight miss at idle, no CEL and hardly noticeable. We have a cat back dual exhaust with turbo muffler, so noise interferes with judgment. We also have a K&N cold air intake that needs regular attention, so we chalked it up to a dirty filter.

At 100,000 miles we changed the plugs, and all coils checked out fine.

At 118,000 miles the miss became more pronounced, but still within tolerance, no hesitation, no sluggish starts.

At 124,000 miles, added a bottle of "Restore" fuel conditioner. About 20 miles later, the engine developed a hard miss on cylinders 4 and 5. Performed compression check, 3-5 140-155, 1 & 2 115-125. So figured the typical 1 and 2 are responsible for the mild miss due to the head problem. Still trying to figure out the hard intermittent miss on 4 & 5, now pretty much limited to 5. Going to pull the fuel rail and injectors to test. Local mechanic quotes $2000 to remove and replace the head, machine shop quotes $400 to repair. Called GM - got nowhere. They said they offered some help within 100,000 miles, but since a bulletin was sent out, they wash their hands after that or 6 years. Go figure.

As for a class action, either there are no attorneys with H3s that have read this thread, or they know it's a loser.

Just got a 2013 Escape with 7000 miles. 8 recalls, new A/C compressor, new water pump on the first dealership oil change. Pick your poison.


23rd Mar 2015, 10:19

I have a problem with the 2006 H3. Every time I let it warm up, then take off, I come to a stop - it turns off. I don't know the deal with it. No engine light on at all.

25th Mar 2015, 02:40

My 2006 H3 with 55500 miles has had the check engine light on for some time now. Was idling a little rough. Took it in to a GM dealer, and yes they say the cylinder head needs to be replaced. Now for the first time I see online, here and other places, everyone seems to be having this same problem! The cost at the GM dealer is 4300, and I will not have it done there for that much, no way. Was looking to sell it anyway as I need a truck. Makes me think hard about getting a GM product again.

25th Mar 2015, 10:49

Try a Ford Edge or Explorer. I have 135k on my Edge crossover and love it. No engine issues and it is pretty quick. I like the SEL AWD model. Or go with the larger Explorer. Truck wise, I have a Silverado and it's been great too.

These specialty vehicles are not for me. My son owned a Range Rover and was extremely relieved to unload it. He bought it for image and doing real estate. Air suspension and engine issues much like this review. I would rather own a more main stream plain vehicle, and add a few nice options. Save a lot of extra image money buying it and dealing with it maintenance wise later. I'd rather have extra money to take nice vacations instead of car payments and repair bills for engines.

6th Apr 2015, 20:09

Well I can join the club. I had a water pump, thermostat, and axle seal driver put on in June 2014. $550.00.

Then a throttle body 02/21/2015. $527.95.

Then had to have another water pump replaced along with the radiator and thermostat. $550.37.

Then 2 days later. the check engine light comes on and it's blowing coolant. Took it to a shop specializing in Hummer work, and he said it had more problems and it would be cheaper to replace the engine than to fix. Looking at $6000.00.

I have a 2007 Hummer H3 with 102,000.

8th Apr 2015, 23:29

I have a 2006 H3, and had the 1st head put on at 20000 plus miles. I would have problems now and then, and they would say they fixed it.

Come about 81000, still having what they said was ignition coils 3, 5, and had 1 also later. GM paid for the head because the GM dealer I took it to looked at my history of problems. The old dealership put on the wrong head - GM was supposed to put on a certain replacement head. The earlier head was not the one that should have been put on. The new dealership put on the new one. Runs OK. Was happy about the service I had received. I still ended up putting money out, but not like I thought it would cost me.

I have talked to others with the 2006 and they have never had any problems. Me, I am planning on selling mine and I'll get an older truck to pull my boat. Or throw my hands up and put a V8 in it. They do feel they have a great engine in the 3.5L 5 cylinder. I like my H3 except for the engine.

Had coil 3 go out at 99000. It is an issue I plan on not dealing with.

14th Apr 2015, 02:06

I am wondering if anyone can tell me the cost to rebuild a Hummer H3 2006?

12th May 2015, 05:32

I purchased my H3 on Dec 5 2014. Had the same problems.

The dealership supposedly replaced the head as my #4 cyl misfired 492 times out of 500!!

Just as soon as I got it back, after a month of the dealership having my vehicle, the engine light would come on intermittently... Now it has been on solid for over a week.

12th May 2015, 05:34

It's cheaper in the long run to buy a new motor - 4000.

19th May 2015, 17:06

WOW! I have a 2006 H3 that I purchased brand new! I have experienced misfire code P0300 for about 6 years now, always coming back to cylinders 1 & 5. Consistent starting problems, and after waiting 10 minutes it will fire right up and I'm on my way! GM will take 0 responsibility! And I now have 145K miles and am having to repair heads & who knows what else! I am in on a class action suit, just let me know what you need! Vancouver Wa.