I have 2007 h3 i5, I've been noticing my temp guage running between 5/8 to 3/4. All the time. Change radiator, hoses, coolant and thermostat. I can't figure this out, it's only been in 70s here in ga but I'm afraid of when it gets really hot. I've heard a extra trans cooler may help.
please any advice will be greatly appreciated

 

H3 Gauges are notoriously inaccurate. While mine always runs right at the 1/2 point on the gauge, others have said they run at 3/4. Without a scangauge, or an OBD adapter and a scan app (like Torque), you have no idea what the actual running temps are.

Is this a new situation? Did it used to run at 1/2, and now runs at 5/8-3/4?

 

I never payed attention until recently when I had trans rebuilt

 

I have an 07 as well .Always ran just below half mark. Over winter my t-stat went bad, stuck open .since replacing that I have had similar issue ( post is below here ) . When I stoo at traffic light, I go to 3/4, when moving back to just about half.

My actual readings at half are 203, at mid way to 3/4 line, it's 212,. At just below the 3/4 mark it's about 219 .

You need to read actual temps and not trust the guage . But I understand your problem as mine was always fine, until recently, now it's all over the place as well.

 

Lot of mechanics keep telling me that hummer are supposed to run little high but I'm worried when it gets really hot here in Georgia

 

I have a 2007, used to say 1/2 after I had a new radiator put in its at 3/4. I live in California and it can get hot, never had it overheat since new radiator, going on 2 years.

 

I hope not,
I want to thank you all for answering and help

 

had an 07, now a 10. both never got up to mid point. top temp hit 205 even with a blanket over the grill on a hot day...if everything is working right.....its cool!

btw, in 58 yrs of driving 35 cars ive never changed a fan clutch.

 

Temp can be dropped several degrees by adding PURPLE ICE to the DEXCOOL.

 

For about the 2 millionth time..... 3/4 on an H3 temp gauge is 100% completely NORMAL. Feel free to search this, it has been beat to death.

The gauge in the dash is like an idiot light with a needle. When it is in the red, then be concerned. Otherwise, drive on and find something else to worry about.

If you mud bogged your 3 and got dirt and crud up in the radiator, rinse it out, even use some mild soap then rinse it thoroughly.