The contact owns a 2006 Hummer H3. While driving at 65 mph, the check engine light illuminated. The vehicle was taken to an independent mechanic for diagnostic testing. The contact was informed that there was a misfire in cylinder number four. The vehicle was repaired, but the failure recurred. The manufacturer was notified of the failure. The approximate failure mileage was 133,338.

- Las Vegas, NV, USA

The contact owns a 2006 Hummer H3. The contact stated the vehicle failed to start. The failure occurred several times. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 130,000.

- Jacksonville, FL, USA

The contact owns a 2006 Hummer H3. While stopped, the check engine warning light illuminated, the vehicle started to shake, and then stalled. After several attempts, the vehicle was able to be restarted. The failure recurred multiple times intermittently. The vehicle was taken to a dealer where it was diagnosed that the cylinder head needed to be replaced. The vehicle was repaired, but the failure recurred. The manufacturer was notified of the failure. The approximate failure mileage was 80,000. Updated 1/12/16

- Philadelphia, PA, USA

The contact owns a 2006 Hummer H3. While driving at approximately 70 mph, there was smoke and an odor coming from the air conditioner. The cruise control failed and the vehicle stalled. The vehicle was able to restart after a few attempts. The vehicle was driven to a dealer where it was diagnosed that the cam actuator needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 100,000.

- Topeka, KS, USA

GM has a security system called passlock that over time seems to fail and trips a "failure" and flashes a key symbol on the dash and disables starting your vehicle until it resets 10 minutes later. This occurs to my wife almsot 50% of the time she tries to start her vehicle. So far GM has come forward with a fix yet I've seen posts on Hummer forumns from hundreds of owners. This has many safety concerns as well as just being a general annoyance: 1) in las vegas we routinely see tempatures over 110F. If the system trips and you have to wait 10 minutes in that heat it can be deadly 2) missing appontments or being late to work because you vehicle intentionally is disabling itself it unacceptable 3) groceries cold/frozen stuck in the heat for 10 minutes waiting for a reset get ruined 4) my wife when alone is stuck waiting outside the vehicle in the heat or locking herself inside waiting for the system to reset can leave her exposed to criminal types

- Las Vegas, NV, USA

On several occasions the engine has loss power in traffic and slows down to 15 miles an hour. Once on the highway causing other cars to swerve to avoid rear ending us. Another in rural traffic causing other cars to go around. We are always leary when driving this vehicle. Our mechanic has looked it over on both occasions and can not find anything wrong and we have the best mechanic in town. GM should pay a little now and recall this vehicle and fix what's wrong instead of a lot later when someone's family is killed. I bought this car for my wife to Transport our grandchildren to school and after school events every time she gets in that thing I worry but because I bought it for her she is reluctant to sell. GM please fix.

- Kalamazoo, MI, USA

Rough idle, engine light appears. In past have been told have been told gas cap related or poss thermostat or intermit misfire. Today dealership says cylinder #2 not working. Need to replace. At a cost of $3000+. related to L52 engine concerns & intake valve seats. Including Colorado & canyons. Why are some recalled, and/or fixed on manufacturer's dime, but not others? GM knew of concern, (thus changed to llr engine). Mine fits the year and well below the VIN #. why should 287591 H3 owners have to pay for GM's mistake?

- Rock Island, IL, USA

The contact owns a 2006 Hummer H3. The contact stated that the vehicle accelerated independently and stalled. The vehicle was not diagnosed or repaired. The manufacturer was not notified. The failure mileage was 85,000.

- Sacramento, CA, USA

Own Hummer H3 2006. Randomly, traction, failure, reduced, power, stab sys, service. When this happens, the car can be driven only around 40 mile per hour which is very dangerous on free way. It only happens randomly. Usually after rain or cold weather. But the dealership said they cannot reproduce the problem. Called GM, they told me they cannot do anything although they say there is an investigation and there might be future recall.

- Corona, CA, USA

The contact owns a 2006 Hummer H3. The contact stated that the engine warning light illuminated intermittently. The vehicle was taken to the dealer, who stated that the engine head and/or another component needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 82,600.

- Syracuse, UT, USA

Learned that our vehicle was known to GM in 2008 that they had a design defect that caused pistons to fail. The check engine light came on, we went to GM dealership, called their corporate offices after learning the knew of the piston defect since at least 2008. I'm sure they have replaced millions of pistons during warranty but the cost of replacement is $5000. We leased this vehicle for 3 years and are purchasing it. GM refused to assist us in fixing this issue. They are dishonest and unprofessional. How many vehicles in the us have piston failures as a design defect? they should have issued a recall.

- San Antonio, TX, USA

The vehicle was purchased used on a Saturday with the dealership not advising us there were any issues. The next day we headed to the lake and 20 minutes later we were sitting on the side of the road. The vehicle was idling very hard with RPM going crazy. Now over a year and several visits to the shop later we are still experiencing the same issue. When the vehicle is initially turned on it will not move. It has to sit for about 3 minutes with the engine light flashing. If you try to push thr gas nothing happens. The vehicle idles very hard. It is only firing on 4 cylinders and the dealership says that GM is aware of the issue. They said it is a "bad batch" and will just have to keep replacing the head to fix the problem. This is not fair to the consumer and needs to be addressed by GM.

- Blountville, TN, USA

While driving at 45mph all systems shut off. No power steering nothing. The car would not restart. This happened multiple times with out warning.

- Seminole , FL, USA

Car has been spontaneously stalling while driving at high speeds. Engine cuts out, power brakes and steering fail, no radio, etc. Vehicle loses all power. It is terrifying. Has happened at least 3 dozen times now. Several visits to dealer could not pinpoint problem. Dealers unable to duplicate stalling, although it has happened to me regularly for months - ie, every time I drive the car (with my two babies) for an extended period on the highway.

- Cotuit, MA, USA

Owned the car since 2006 with no problems--regularly maintained, 125,000 miles. My wife took it to the shop where she was told the engine had "low compression." After the review, the manager said he had bad news, that the car needed to be traded in/sold immediately and not to drive it until it was because the piston was defective. I verified the results with 2 other mechanics that the 5 cylinder H3S lose compression out the blue. The shop manager basically told me that I need to sell/trade in the vehicle, but not to drive it until I had done so, apparently this issue has happened to 06 H3S religiously where the compression diminishes and leads to the engine dying. We feel like we've been punched in the gut by Hummer. How can a car perfectly maintained all of a sudden have "low compression" and lead 3 professionals to advise us to sell it it as soon as possible? this has been known by Hummer (pip3935D) and they did nothing about it. We called GM and they wanted to look at the engine to diagnose it themselves. Pistons 2 and 3 were bad. Our VIN number is covered by the pip3935D but the dealership refused to acknowledge this. They refused to assist us unless we paid $6000 for the "repair"--but this issue will re-occur. I have made a call to GM corporate but have yet to receive a reply. In the meantime we still owe over $4000 on this vehicle that we leased in 2006, then purchased. Our vehicle is unsellable and we don't have $6000 to fix this known Hummer 2006 H3 defect. GM has been aware of the defect since 2008 and refuses to act like professional, understanding, compassionate individuals. I will never purchase or recommend the purchase of a GM again based on this life-changing experience. How can a dealership (that the us government bailed out of bankruptcy) treat its customers this way? we have spent $30,000++ since leasing/purchasing it in 2006.

- San Antonio, TX, USA

Owner the car since 2006 with no problems--regularly maintained, 125,000 miles. After a recent long trip my wife took it to the shop where she was told the engine had "low compression." The shop was trusted 100% and been used for decades. Service manager said they would see what they could do about the low compression and that they would have to check each of the pistons. After the review, the manager said he had bad news, that the car needed to be traded in/sold immediately and not to drive it until it was. I verified the results with 2 other mechanics that the 5 cylinder H3S lose compression out the blue--common among 5 cylinder H3S. The shop manager basically told me that I need to sell/trade in the vehicle, but not to drive it until I had done so, apparently this issue has happened to 06 H3S religiously where the compression diminishes and leads to the engine dying.. it's a possible to buy a used engine with the possibility that the compression could die again. Needless to say, we feel like we've been punched in the gut by Hummer. How can a car perfectly maintained all of a sudden have "low compression" and lead 3 professionals to advise us to sell it L it as soon as possible? this had to have been known by Hummer and they did nothing about it. Meantime, we are probably over/under on the vehicle and will have to get rid of it.

- San Antonio, TX, USA

First of all, the date of the incident is very vague considering it's been happening most of the life span of the vehicle. Ever since the vehicle reached 30,000 miles the check engine light has been going on and off periodically. Now there is around 85,000 miles and I can honestly say the check engine light has been on for most of the life of the car. The code is always P0300. This is due to a random misfire in the cylinder heads. I have had this car long enough to say this typically happens during idle. This car has always had a rough idle. I would say ten percent of the time it's a smooth idle. I always use good gas, clean oil and up to date maintenance on this vehicle and I never stress the engine due to it's feeling of it being so fragile. Going online I am astonished to find so many with the same exact problem. GM had the same recall on the inline 5 cylinder canyon cylinder heads. This is the same problem we are having with our inline 5 cylinder engine heads. GM needs to put this on recall. Fix their mistake and keep this check engine light from going on every time I park my car, start my car or simply idle. Many would be grateful if this was recalled.

- Philadelphia, PA, USA

Blower motor quit working. Took to dealer said needed motor wiring harness and resitor. They said the wiring harness caught fire and fused together. Cost of $300 to fix. Fire hazard.

- Lexington, KY, USA

The contact owns a 2006 Hummer H3. The contact stated that the vehicle would not accelerate over 50 mph. In addition, the vehicle would sporadically stall with the illumination of the check engine warning light illuminated. Also, the vehicle would overheat when the failure occurred. The vehicle was taken to a mechanic where a diagnostic was performed. The dealer advised that the catalytic converter, air sensor, coil springs, and the spark plugs needed replacing. The vehicle was repaired but the failure persisted. The failure mileage was 80,000 and the current mileage was 87,000.

- Greensboro, NC, USA

The check engine came on and I took it to my dealership to have it checked out.they performed a diagnostic that located the failure at the engine head cylinder (engine missfire). The vehicle was not repaired. The manufacturer was contacted and denied assistance with the repair because the vehicle warranty was expired. The mechanic stated it was due to an inferior soft metal used to manufacture the heads which caused a loss of combustion when the engine was idling. The blowback at idle was what was causing the engine light to illuminate. Mechanic also stated this problem was a recurring problem in this 5cyl engine which is the same engine that is in the Colorado pickups and is covered under a GM recall in the pickups but not the Hummer. The mechanic stated that the issue will only get worst. Please help as I was given a price to repair of approx. $3183 if I was going to pay for the repairs myself at the dealership. What can a person do when this is a known mfg defect, many complaints about this issue with no recourse.

- Peoria, AZ, USA