Hi All,

Mthoodh3 wrote:
"the thermostat is located on the bottom of the radiator and you need to remove the front drivers side wheel to access it."

Really...wow, what a weird place to put that!

No modifications on my Hummer. Its all stock, except for the tires, which are Goodyear Silent Armors. - Very cool tires BTW.

The coolant level is actually a bit high. Its about 2-3 inches above the mark on the water bottle. The coolant is a bit dark (kind of brown), so I think that I may just flush the radiator and change the coolant. I may also swap out the thermostat, as its almost 60K miles old (almost 6 years old) and it could be getting stuck. I'd hate for it to lock up in heavy traffic and overheat my engine.

Thanks,
Fulano

 

The thermostat is NOT on the bottom of the radiator,so be careful of people who make up answers. There were pics of the job here b 4.
And the coolant cannot go up without "something" being added.
You better quickly check the tranny fluid.You may have a leaking rad.
And,no its not better to be running cooler. If the manufacturer wanted a cooler engine they would put in a 160 thermostat,or none. Within reason,the hotter the better.

 

Check your coolent and your trans fluid. If they are both discolored your radiator has a leak between the two coolers in the radiator.

If not, then swap out the t-stat for another of the same temp. The PCM does not like to see low temps. It monitors the temp from cold start to a certain temp and will adjust the engine parameters accordingly.

X2 on the t-stat not being anywhere near the bottom of the radiator. It is on the Dr side near the front of the motor. There is a great write up on here about swapping one out.

 

I should have been more clear in my response when stating BOTTOM of radiator when i mean LOWER radiator, as in you are not changing the thermostat from under the hood, you must remove the wheel and wheel lining to access the LOWER side of the radiator where the rad inlet hose is located. in no way do i make up answers on this forum and before you call someone out you should find out where the thermostat is located for yourself on an H3.

Fig. 29: View Of Radiator Inlet Hose & Thermostat Housing
Courtesy of GENERAL MOTORS CORP.
2. Raise and support the vehicle only high enough to access the thermostat housing (4) through
the wheelhouse. Refer to Lifting and Jacking the Vehicle .
3. Remove the left wheelhouse liner. Refer to Wheelhouse Panel Replacement (Front) or
Wheelhouse Panel Replacement (Rear) .
4. Position the J 38185 to the clamp (3) in order to remove the radiator inlet hose (2) from the
thermostat housing (4). See Special Tools.

 

I purchased the t-stat with housing, $23.00 shipped new from amazon.. ACDelco 15-11073 OE Service Engine Coolant Thermostat Housing.

Thermostat Replacement

Tools Required

J 38185 Hose Clamp Pliers

Removal Procedure

1. Drain the cooling system
2. Raise and support the vehicle only high enough to access the thermostat housing (4) through the wheelhouse.
3. Remove the left wheelhouse liner.
4. Position the J 38185 to the clamp (3) in order to remove the radiator inlet hose (2) from the thermostat housing (4)
5. Remove the thermostat housing bolts.
6. Remove the thermostat housing from the engine block.
7. Clean and inspect the thermostat housing.
8. Clean and inspect the sealing surface of the engine block.

Installation Procedure

1. Position the thermostat housing to the engine block.

Notice: Refer to Fastener Notice.

1. Install the thermostat housing bolts.

Tighten the bolts to 10 N.m (89 lb in).

1. Position the J 38185 to the clamp (3) in order to connect the radiator inlet hose (2) to the thermostat housing (4).
2. Install the left wheelhouse liner.
3. Lower the vehicle.
4. Fill the cooling system.
5. Inspect all sealing surfaces for leaks after starting the engine.