radiator is made of plastic, super crappy. Why would GM even attempt to use a plastic radiator?? Especially in a 4wd . Failure caused by metal rubbing against radiator. This is supposed to be a luxury suv, and its put together with cheap plastic fasteners wherever they could. Taking off road causes additional stress on plastic fasteners causing them to wear out that much faster. Luxury ....NO more like a rattle trap, much less the mechanical issues like Cylinder Misfires ( VALVE SPRINGS? OR POSSIBLE BAD HEAD)/ Overheating (PLASTIC RADIATOR) / Low Oil Pressure at low idle( SENSOR OR ??).......... How many more complaints does there have to be for a CLASS ACTION SUIT????

I sound like a broken record with this radiator issue, smelled antifreeze had it checked out, small leak; cracked around plastic housing area. Called GM checked any recall info of course was told no. I told them it was an ongoing problem with the model, they played dumb and asked If I would them to make me an Appointment with my local dealer. I was given an est. Of almost $1000, laughed and called around until I found a repair shop who replaced the radiator for $530. GM listen up you make the vehicles please stand by them!!!

My husband and I purchased a used 2007 Hummer H3 around July 2013, which we had not driven that often. We took the vehicle in for an oil change and the service center told us that our radiator was leaking "badly" and that we needed to replace the right side drive axle. I could not believe this??

I have read where many Hummer owners are having the same problem, but Hummer/GMC has not done anything about it or had a recall on it. The worse part is that I was also told by another mechanic ( 2nd opinion) that the radiator and axle had to have been defective when we purchased the vehicle. I know that dealerships are trying to make money, but we test drove that truck with our five year old son in it. How could they put our lives as well as our son life in danger. SOMETHING NEEDS TO BE DONE!!!

It should have been covered as a manufacturer defect because the radiator rubbed in the middle on the frame causing it to crack from stress. I've owned 3 Hummers an H2 SUT and two H3's this was my very first problem ever but nonetheless GM should have picked up this tab.

Update from Jul 25, 2012: I did purchase an extended warrantee when I bought this H3 which had 21,000 miles when I got it. I took it to Towbin Bentley and Rolls Royce on Sahara in Las Vegas (It's not Towbin Hummer anymore since they stopped making Hummer's) and they treated me like a Queen. Since they had to keep my baby overnight they simply suggested that they accommodate me with a rental at their expense and they'd notify me when they were done. They called Enterprise who came over and picked me up from Towbin and took me to pick up my rental. It was a beautiful thing, they went above and beyond their call of duty. I'm very happy to say that it was covered under my plan. The bill came to $1645.00 of which I had a $75 deductable for choosing to have work done at Towbin instead of where I originally purchased my H3. The car rental was $67.00 of which Towbin did pick up in full.

NOW THAT'S THE WAY TO TREAT PEOPLE...........