The contact owns a 2007 Hummer H3. The contact stated that the engine was defective. The engine failed to start numerous times intermittently. The engine started after waiting ten minutes and the anti-theft light illuminated. The vehicle was not diagnosed nor repaired. The manufacturer was notified. The VIN was unknown. The failure mileage was 74,000. Updated 04/22/16

- Moore, SC, USA

The radiator has a crack in it which is a very common issue...needs to be recalled. My H3 was idling rough and would shut off. Had to replace throttle body and solenoid. The anti-theft acts up and the H3 won't start have to wait 10 minutes. The ac blower and connector burnt paid for it to get fixed then the recall comes out 7 days later....still haven't been refunded for that. I have all the issues on my 2007 H3 that should all be recalled and fixed at GM expense. Sunroof drains get clogged all the time and have water leak onto the floor which makes the ABS light trigger on and off. Issue after issue which GM doesn't take any responsibility for. It looks like it's time to sell the Hummer H3!!

- Tallahassee, FL, USA

Rebuilt transmission twice cleaned throttle body replaced exhaust manifold two O2 sensors replaced the radiator the heater core a fuel pump relay and this engine light still will not turn off it says torque converter clutch solenoid I'm disgusted already GM fix ur [xxx]. information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Houston, TX, USA

Takata recall miss fire ignition coil theres way to many complaints about this if theres nothing done about this its the last time im buying a GM automotive to get it fix cost almost $3000 dollars thats not good for your business

- Wichita, KS, USA

The contact owns a 2007 Hummer H3. The contact stated that the check engine warning light illuminated. The contact received notification of NHTSA campaign number: 15V421000 (visibility) and stated that the parts needed for the repair were not available. The contact stated that the manufacturer exceeded a reasonable amount of time to the recall repair. The manufacturer was made aware of the failure. The failure mileage was 140.000.

- Raleigh, NC, USA

While driving at 65 miles per hour the vehicle dash lit up all service lights the vehicle went into reduced power mode not allowing the vehicle to exceed 40 mph and ABS sensors came on staying traction fail, ABS fail, began to stutter and stall. Took to shop. Vehicle running codes for spark plugs, replaced spark plugs. Few weeks later did it again, this time saying throttle body. Replaced it, a month later did it again, each time in major traffic having to pull off roadway to avoid an accident. This time says misfiring, throttle body, ABS, TPMS, thermostat, etc. Take it to have compression test run and system says cylinder failure. Do research on issue and find that there are hundreds of complaints about this online having caused accidents and thousand of dollars spent by consumers after having accidents but no known fatality so GM will no recall or honor the issue repairs. Almost all of them happening at 100K miles.

- Mount Washington, KY, USA

Vehicle would not start called dealership where car was purchased - replaced ignition switch after diagnosis. Since then have had repeated episodes of vehicle ignition/electrical just shutting completely down on different occasions. I could be sitting or approaching a stop light vehicle shuts down upon taking off or idling down, vehicle also shuts down when making turns as well. It occurs so infrequently and has no pattern but it is indeed a safety concern because I have to put on the flashers and take time to restart the engine all before someone runs into me.

- Raleigh, NC, USA

Engine check light came on for very short period of time then went out. About a week later it came on again. Went to Chevy dealer who ran a quick code check which indicated the number 5 cylinder was misfiring. The Chevy dealer indicated the engine/power train warrranty had expired and the problem could be from injectors, plugs, coil and valves. Initial computer check would cost $135. Vehicle is sitting in my garage awaiting money to get it checked.

- Fairfield, CA, USA

The contact owns a 2007 Hummer H3. While driving approximately 40 mph, the vehicle shook violently and stalled without warning. The vehicle could not be restarted. The vehicle was towed to the dealer where it was diagnosed that the engine or the cylinder needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 56,800. Updated 03/10/15 updated 6/17/2015

- South Plainfield, NJ, USA

Just had my Hummer in 2 weeks ago at the GM dealership to have the ignition switch replaced. Had been dealing with it stranding me and my kids for 10 minute periods long enough. ( sometimes longer) while it was in there we also had to get the radiator replaced due to it being cracked. Now 2 weeks later my check engine light and traction light have come on. The traction light saying service sab system. After reading all the Hummer problems I can not believe that there was not a recall on both the ignition switch and radiator. The ignition switch being faulty put me and my kids in situations in places for long periods of time that were not safe and at times we were very cold since we can have below zero weather in Colorado. The ignition not recognizing the key causing the anti theft system to activate is recall issue and GM you should be taking responsibility for this!!

- Ault, CO, USA

My vehicle has a cracked radiator and according to other Hummer owners this is a common defect that happens to these vehicles. His over heating cuased me to pull over on a busy highway were I could of been hit and killed, total failer of vehicle electronics, GMC does not want to work on the vehicle that is not under warranty, because of the many problems wth this vehicle. This crack is were it is wearing near the motor.

- Palm Bay, FL, USA

I purchased this vehicle, new in July 2007. Since that time I have meticulously maintained the vehicle. On 7/28/14, parked at home. Got out and smelled coolant vaporizing (distinct smell). I am a retired master mechanic, with 44 years experience (currently age 60). I examined the radiator, rinsed it off and dried it, pressurized the system to discover a hairline crack in the upper, plastic tank of the radiator in an area with no impingement of other components, no trauma, and no rough use, ever. I caught it at the very first manifestation, solely by the smell. Examining the vehicle closely to discover while my radiator had only this hairline crack in a location of no-stress and no impingement of other components. Research further to discover this is a very common problem with the H3, from 2006, 2007, 2008 and 2009 models all in the 50,000 to 100,000 mile readings. The replacement of the radiator at local GM dealer, with cooling system service was extremely expensive as the replacement of the radiator requires the receiver dryer of the air conditioning system to be disconnected which requires discharge and recharge of refrigerant R124A. I saved the defective radiator. There is no other wear nor damage. The internal cores were clear and clean like new. No obstructions, dirt nor wear. In other words I was forced to replace a perfectly good radiator for 1 hairline crack on the upper plastic tank. This repair, including all courtesy discounts from the selling dealership, as I had been an auto repair shop owner and loyal customer for 30 years of my life, cost me $966.57. NHTSA should do a formal defect investigation on all the Hummer H3 models and any / all other GM like-type vehicles with the plastic tank radiators which could cause a serious accident or death.

- Palm Beach Gardens, FL, USA

Radiator had small leak, has since increased over last 3 years. Not covered under warranty and every H3 owner knows this is a defect that needs to be recalled.

- Warwick, RI, USA

My radiator tank cracked right across the top compromising my cooling system. This turned into a bigger problem as the transmission oil cooler was not operating correctly and eventually destroying my transmission. I had to spend over $2K to have a refurbished tranny and new radiator installed.

- Deerfield Beach, FL, USA

Less than 1 year ago, I had the radiator and transmission replaced in my vehicle. I have recently noticed the smell of antifreeze coming from my hood after long trips. The radiator that was installed in my vehicle 10 months and 8K miles ago has developed a crack in the top tank. There is dried coolant spray across the top of my engine and a crack forming right behind the lip of the frame of the truck.

- Deerfield Beach, FL, USA

44,000 miles check engine light came on. Took to dealer I had a cylinder 5 misfire code P300 couple thousand miles later my truck was still showing multiple misfires. I had to replace the radiator because it was leaking and thermostat at 46,000, April 2011 at 65,000miles my transmission went out completely and had to be replaced July 2012 air stop working took to dealer they said I had to replace the fan blower motor resistor. Researched and founded this was a known problem for Hummer the motor gets to hot and melt causing the fan blower to go out. Several months later check engine light came on several more times took to the dealer said they couldn't find problem and cleared code my check engine light came on again so I took to auto zone diagnostic showed cylinder 5 coil multiple misfire so I had spark plugs changed alone with all five ignition coils. Couple months later check engine light came on again took it to dealer diagnostic test reveal code po 300 again and couple other codes dealer said my truck had an emission leak. Multiple misfire, cylinder 5 and a small crack in the head. I didn't understand how that magically happen. I paid the dealer to fix this on March 2014. A week later check engine light came on again. Took to dealer diagnostic showed emission leak apparently they didn't fix it the first time. Week later check engine light came on again took to dealer and diagnostic test reveal torque converter clutch solenoid.dealer said I need transmission replaced. I'm confused at this point the dealer put a newtransmission 3 years prior.my truck has never been over the road. I only drive locally. Now at 103,000 miles the dealer is saying I need another transmission. Something is not right here. After researching I've found thousand of Hummer owners experiencing the same problems I've experienced. Something needs to be done to protect consumers.

- Arlington, TX, USA

I own a 2007 Hummer H3 with 66000 miles on it. It has been diagnosed as having a bad head due to the use of soft metals for the cylinder sleeve. Due to this, there is sudden reduced power. The cost of this fix is about $4500. My truck began with a check engine light on (autozone) said it was a misfire on cylinder #5. I went to the local dealer and asked them to look at the truck. They diagnosed it as a #5 cylinder having the compression leak of 90%. in looking on the internet (at Hummer forums), I observed that quite a few Hummer H3 owners were writing in about their experience with misfires and bad heads, at about the same mileage. I think this needs to be looked into and that GM should be ordered to do a recall. This is the same problem they had with the 3.5L engines they used in their pre-2007 Hummer H3 and Colorado. I am going to write my congress rep and ask that with the problems that GM is having right now, that this also be moved forward and that they order an investigation. Any other Hummer H3 owners with the same problems should do the same thing.

- West Bend, WI, USA

Smelled radiator fluent when I parked into the drive way, popped the hood and saw that the liquid splashed all over the engine and parts as well as on top of the plastic fan cover, which seemed odd. Couldn't find the leak in the hose. Looked at the Hummer forum that I'm a member of and lord behold there was a big topic of radiators cracking and breaking in the same places with the 2007 models. No recall has been issued, so no recall has been submitted. But it's a well known defective radiator problem that GM knows about but won't recall. So they decided to make a new radiator that fixes the problem for the 2007 Hummer. The problem is the middle pin that holds the radiator rubs the neck and starts a cracked under the styrofoam, thus the right drivers side cracks in the same spot as well on the plastic side. Hundreds of H3 owners had this happen to them and post pics and what not, but still no recall. This problem is ongoing and nothing is being done. I have spoke to the Hummer customer service and they contacted the local GM and they scheduled my scheduled date to take my H3 in Feb 17 2014, @ 8 am at the local GM dealership and hopefully they will fix this issue and not charged me to fix due to the fact that they know the problem and have done nothing to fix it. But it's been know that they will not fix the radiator and they say it's due to climate which is false because every H3 owner has it break in the same place, and have submitted countless tickets.

- San Antonio, TX, USA

The contact owns a 2007 Hummer H3. The contact stated that the vehicle lost acceleration power. The contact took the vehicle to the dealer where it was determined that the valve seals in the second and fifth cylinder heads had failed. The dealer stated that the fifth cylinder head was the most dominant and caused the majority of the failure. The contact stated that both cylinder heads had a 70 percent leak. The failure was reported to the manufacturer. The VIN was not available. The failure mileage was 65,000 and the current mileage was 80,000.

- Roseville, CA, USA

The contact owns a 2007 Hummer H3. The contact stated that while driving 50 mph, exhaust fumes filled the vehicle. The vehicle was taken to the dealer for diagnosis where it was advised to the contact that the manifold gasket needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximated failure mileage was 160,000.

- Jackson , WA, USA