possible overheating or faulty thermostat?
 

I have a 2006 h3 3.5l base. at 105,000 kms I had the motor replaced due to the infamous bad head/valve problem, overheating, and a cracked bellhousing. Motor was replaced by dealer and a new thermostat and water pump was also installed to prevent further overheating. The day I got my hummer back (approx 5 months ago) on the drive home I noticed my heat guage went up to the 3/4 mark. I took it back to the dealer and they checked it out and told me the engine was running at the proper temp and the guage might be faulty.. so I listened to them and never thought anything of it. Once I start driving, after about 5 minutes of driving the guage always gets up to 3/4. Sometimes after a 20 minute drive I shut it off and when I walk by the hood I can feel lots of heat (more than usual). The temp outside is 28 degrees celcius. Also it does not throw any codes
Now I was wondering if what I am noticing is normal or if I should get it looked at? maybe the thermostat they put in was faulty. I have driven it for 7000kms after the new motor.

For the record, I love my h3. Ive owned it for a year next month. Im 21 and this is the first vehicle I have ever "worked" on. Ive done all maintainence including tranny flush, transfercase flush, both axle fluid flush, coolant flush, new shocks all around, and I'm kind of hoping the thermostat is faulty so I can change that too.

You really need to read the Coolant temperature from the OBD II port to see if it's too hot or not. There has been much consternation regarding the guage readings and "it's just a dummy light with a gauge attached" (according to DocOlds) is the best description of it I've seen. I would say that the extremes of the gauge are not very sensitive but from 1/3 to 2/3 (or even 3/4 Hot) it is very sensitive and a big difference on the gauge may not be that much in actual degrees in the motor.

3/4 is not overheating and is normal. Your H3 has layers of overheat protection, and you are not even close to the first one.

Search it out, there are many other threads by the paranoid here. :p

Change the t stat
 

You wont rest till you do and its cheap but some work. Put the old one in pan of woota and bring it up slow to boil,see if when it opens,you'll learn something for all of us!
On the hottest days this year I have not seen 1/2.
The temp is monitored electronically by the computer for complete engine performance control. The computer converts the temp data into voltage to drive the meter so its accurate,not like your grandads old clunker!
Having said all of that,it would seem that the computer would warn you if it was too hot?
An obd2 readout should be done.

If you were aware of the TSB regarding the Temp gauge you would realize the gauge is NOT accurate. It really is nothing more than an idiot light with a needle. When the needle gets to red, pay attention, otherwise without a scanner, you have no idea what the actual temp is.

The TSB essentially said when customers raise a concern about the temp gauge (at approx 3/4 or slightly more) the tech is to scan the actual temp through the OBDII port. If it is normal leave it alone..... then is goes on to say, if the customer continues to complain, swap out the instrument cluster with a new Temp gauge that reads lower, no actual cooling system work is suggested. So the answer to the paranoia is to put a different inaccurate gauge in the vehicle so the customer thinks all is well, without doing anything further.

At the 3/4 mark most scan readings will be in the 215-225 F range, not even close to overheating.

This "perceived" overheating regarding the H3 has been beat to death on the various forums, a simple SEARCH will bear that out.

Thanks for the info, mine operates slightly below the 3/4 mark. I have had my H3 for just a few months and I was concerned it was running hot.

GED10

Been reading the problems with the temp gauge, my 06 H3 reads between 1/2 and 3/4 always, I just replaced the thermostat and have checked the cylinder and radiator hose temps, cyl head-197, inlet and outlet hoses both near 180, obdII reads 213. I used a temp gun to check the temps and they were no where close to the obII reading, could my ECT sensor be bad without throwing a code?

Welcome to HF.

Please AVOID digging up OLD as dirt threads in the future.

Between 1/2 & 3/4 is completely normal. 213 is no big deal either when idling while hot outside.

Temp gun is not going to read coolant temp, it is going to read surface temp not what is going on inside. Drive it with a scanner attached and see what it does.

Sorry I did not know how to start a new thread

Oh ****... my h3 went up to 3/4 one time and my radiator started shooting coolant out and it actually caused like $800 of damage. But I actually just started putting beer in the radiator and that fixed it.