So this is been a long road. This is what your h3 temp should be at. In order to achieve this. I replaced water pump, thermostat and temperature sensor. Also have 1 royal purple ice. since I also have new water pump i also added a new tensioner, power steering pump and pulley and belt.

H3 after everything is fixed

H3 heating issues

 

Thanks for posting.

 

The normal temperature should be below the average mark. This is the way it is for all cars. If the arrow is higher, then the car is heating up a lot.

 

If you want to know the actual water temperature. You can buy Scan Gauge. It plugs into your obd port and sits on the dash. You can see water temp, trans temp, Alt voltage, fuel mileage. The only thing you can’t see on the H3 is oil pressure which is lame.

 

Where does the "Scan Gauge" get the input from? I only need the OEM gauge.

 

Looks good.

 

From the ECU. That’s good you only need the basic OEM gauge, but the gauges in the H3 are beyond basic. No alternator, no oil pressure, no trans temps ect.. My 2001 Silverado comes standard with an oil pressure showing psi numbers, water temp that has numbers, trans temp that shows numbers, alternator that shows voltage.

The Hummer dash shows none of this, yet the ECU has the live data. There’s lots you can see using a Tech 2, and that’s how mechanics see what’s going on.

The Scan Gauge is a cool visual tool that lets you see allot this of data too. You can see your average MPG, current MPG, Voltage, Water temp, & Trans temp on the H3. The only thing that’s weird is the Scan Gauge can’t show you oil pressure on the H3, but it does on the other GM trucks. BTW I have a 2009 H3 CE (V8)

Lots of info for $159.


https://www.scangauge.com/products/scangauge-ii/

 

thanks was a little bit lower today actually. overflow was a little empty

 

What temperature were you running before you did all that? What do you think fixed it or did you just replace all the stuff at once?

 

I honestly dont know. I just like throwing parts and money until it works. 🤣 If its easy enough for me to do and i can get the parts off rock auto cheap. I just figured the h3 is running hot. I replaced thermostat with no change. so what else… water pump. which i was spinning the old one with the belt off and it was making some squeaky noise. so replaced it. I was also having some noise coming from the front @hummerz suggested take the belt off and see if it makes a difference. I just decided to replace the belt and tensioner and pulley. This time i went AC delco on those parts and my power steering pump was making some noise so i was like might as well flush the fluid and i already added new tensioner and pulley might as well add a new power steering pump with pulley. I threw so much money at this vehicle. i am like what else can go wrong. 😵‍💫