Leaking Radiator


pretty bad
Typical Repair Cost:
Average Mileage:
80,200 miles
Total Complaints:
7 complaints

Most Common Solutions:

  1. replace radiator (5 reports)
  2. replaced (2 reports)
2007 Hummer H3 cooling system problems

cooling system problem

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2007 Hummer H3 Owner Comments

problem #7

Jan 102018

H3 LX 3.7L V5

  • Automatic transmission
  • 131,000 miles


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????

- Michael R., Las Vegas, US

problem #6

Apr 012016

H3 3.2L

  • Automatic transmission
  • 75,000 miles

H3 2007 Hummer had radiator leak from rubbing near neck of Radiator, should have been recall I here this common.

- Michael H., Bay City, TX, US

problem #5

Mar 072016

H3 X 3.7L I5

  • Manual transmission
  • 89,000 miles

Reading on the web I've found this to be a common problem with H3's not just this year.

- gilorex, Knoxville, TN, US

problem #4

Jan 072016


  • Automatic transmission
  • 92,000 miles


I paid 40,000 dollars for my Hummer (H3) bran new GM made a cheap ass plastic radiator that didn't last. Cost 570 dollars to replaced .

Took my hummer originally to have the thermostats replaced cost 329 dollars to replace drove it home. My wife took it to work the next day and steam was coming out from the hood when I checked it the radiator was bad. I think GM should be ashamed of their self for making a cheap radiator for such an expensive suv. I will never buy another GM vehicle.

- big sexy, Perryville, MD, US

problem #3

Oct 012015


  • Automatic transmission
  • 43,000 miles

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!!!

- lizde, Wilmington, DE, US

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problem #2

Mar 222014

H3 3.7L

  • Automatic transmission
  • 72,339 miles

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!!!

- Kimberly S., Ashland, VA, US

problem #1

Jul 012012

H3 X3

  • Automatic transmission
  • 59,000 miles

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.


- finelegs, Las Vegas, NV, US

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