so i am curious, as a new H3 owner, what is "normal" for the engine temp gauge to read? mine sits at the 1/4 hash mark on the gauge. every once in a while it will creep up to between the 1/4 and 1/2 lines but goes right back down..... i read something about the cooling system keeping coolant flushing through the system and it would cause the engine to never fully warm up. basically always running cold. just curious to see if maybe i have a stuck thermostat or something.....

 

Sounds like someone put a 160 stat in it.

180 is stock, mine sits maybe 3/16" below the half mark.

 

It could be anything from the "dummy gauge" reading incorrectly to a bad t-stat. Plug it into an OBDII reader and check the actual temp when it is warmed up before you start to tear into it. Most of your local auto parts stores will have loaner OBDIIs you can use in their parking lot.

 

Should it be steady around the 180 degree mark when warm?

 

mine always reads right in the middle. I live in Hawaii, so temps from 75-85 year round.
A friend of mine who used to work for Hummer, recommended a 160 thermo. He stated that although the water temp looks low, the engine runs well off of it.
Also stated, H3's tend to run to hot as it is.

 

I posted some temps from startup to hot here recently,cant find my post,as usual!, but i'm thinking it stayed at 190-195.
Those readings were all from my obd2 scantool and separtely a scangage 2 as a crosscheck. my dash gage always reads just under 1/2


I thought the standard tstat was 195. regardless,changing it to a lower temp never makes sense as the manufacturer set it where they design the engine to run best and that's hot.
You can run cold by leaving the tstat out but you will ruin the motor.,hot is best.
I have never had a car that had the gage wandering around unless it had serious problems. it should stay at the tstat temp. unless the outside temp is really high and you cant keep moving. mine doesn't go above 1/2 even idling in july.
the svc manual says the tstat should start to open at 188 and be fully open at 225. the fan clutch kicks in at 185-205.
more when I find my old post,,,

 

You cannot answer that question by simply reading the dash temp gauge. There was a TSB regarding the inaccuracy of what the gauge displays vs actual temp. Truck to truck the gauge can display significantly different positions even though actual temps vary only a little. Essentially, the gauge is an idiot light with a needle, when it gets in the red, you should be looking for a problem, otherwise it ain't worth much.

Cooler T stats are not a good idea, while they were a "hot" idea in the mid-late 90s, the trade offs for a DD are not worth any potential gain. I personally do not consider the OEM cooling capacity of the H3 as robust so I would not want to burden it with additional load. These trucks were designed to burn cleaner and more efficiently at the sweet spot of 188-193F.

 

2006 h3. I would say that's normal as mine is about the same only goes to right under half when it's like 100 degrees out. I also wonder if a cooler temp is connected to having a tow package as mine has one??

 

I may be mistaken but I thought all H3's came with a towing package. Our needle is always between half and the 3/4 mark or a little higher.

 

Not all H3's had the tow package. Tow package is just a new rear bumper w/hitch cut-out, hitch and wiring harness. There is no additional transmission or engine changes for more cooling capacity or stiffer suspension.