The contact owns a 2006 Hummer H3. The contact stated that the temperature gauge had increased several times and when he inspected the vehicle, he found radiator coolant leaking from the radiator top seal. The vehicle was not repaired. The manufacturer was not made aware of the he failure. The failure and current mileage was 83,000.

- Horizon City, TX, USA

Came out of work to find a puddle of coolant on the ground. Radiator plastic cracked. Fluid is on fan and throughout engine compartment. Searched on google and found this is a known issue. GM dealer and customer service acknowledged this is a common issue, however would do nothing about it.

- Lakewood, CO, USA

The service technician diagnosed a cracked radiator, which is a know Hummer H3 issue. They have asked for $850+ to fix what is a known design flaw. www.hummerforums.com/forum/Hummer-H3-17/read-if-your-H3-radiator-has-cracked-leaked-21184/.

- Sachse, TX, USA

I went in to dealer for what I called a fluttering periodic idle. They took a look $200 later told me I had misfire in #2 and #5 and needed new head. You can imagine my comments and he said it is common he just did one last week on the same year and type H3! well I was in touch with GM - the car is out of warranty but low mileage. They did cover a portion and I was responsible for the rest. Well I pick up week later. Was told it was test driven and runs great. I told them it ran great before just the fluttering idle when I stopped at a light. They said you are all set.. many bad words escaped my mouth when I drove home and it was not fixed. The vehicle still drove the same way it did before and the flutter was still there, . so now I have to bring it back again and I made the tech get in the vehicle so he knew what I was talking about and he said well it was brought in for a misfire. Uhhh no it was not. Why has GM not done any type of recall on this if it is known problem. Feel like they don't care since the vehicle is not made anymore what does it matter to them. I could continue but am limited to characters.

- Chicopee, MA, USA

The check engine light went on and off. The vehicle was taken to a mechanic who diagnostic as cylinder #1 misfire. Compression test failed due to cylinder leakage. The main problem was to at the time of manufacturing the engine soft metals were used with the heads. I was told I need to replace cylinder head and related parts. Contacted GM Hummer division informed them of my problem with my 3.5L, 5 cylinder engine and ask them for assistance since they did a special extended warranty for the 2006 Colorado and canyons with the same engine problems. They refused to help.

- Raymore, MO, USA

The contact owns a 2006 Hummer H3. The contact stated that while driving approximately 65 mph, the vehicle suddenly stalled. The check engine light illuminated on the instrument panel during the failure. The vehicle was taken to the dealer for a diagnostic test. The technician stated that the engine's cylinder head would have to be replaced. The vehicle was not repaired. The approximate failure mileage was 103,000.

- Orlando, FL, USA

The contact owns a 2006 Hummer H3. The contact was traveling 50 mph when the smell of coolant emitted inside of the vehicle and white smoke was visible from under the hood. The check engine warning light illuminated intermittently with the failure. The contact confirmed that the engine was over heating. The vehicle was taken to a private mechanic who confirmed that the radiator needed to be replaced. The manufacturer was contacted. The vehicle was not repaired. The failure mileage was 65,934 and the current mileage was 65,936.

- Rayne, LA, USA

The contact owns a 2006 Hummer H3. The contact stated that the instrument panel displayed a warning message that read 'reduced power service stabilizer system tracking failed' and the vehicle failed to accelerate beyond 40 mph. The vehicle was taken to the dealer and was repaired. The failure continued. Both the dealer and the manufacturer were unable to further diagnose the failure. The failure and current mileages were 70,000.

- Tallahassee, FL, USA