Canadian Hummer Club Forums

I've seen a number of people mention how the temperature gauge on the H3 can really be all over the place, specifically worrying what is 'too hot' on the temperature gauge (since there are no numbers) especially on a warm summer day. Myself included, I was getting worried this summer as the gauge kept creeping higher and higher...



I found according to GM this is perfectly normal, or at least how the vehicle was designed to operate. The thermostat should begin to open at 90 Celsius and be fully open at 107 Celsius so that's your operating range. With my ScanGauge I can keep an eye on the actual temperature with the digital readout while also keeping an eye on the dash gauge to see what needle positions qualify for 'normal' or at least fall within that operating range.



When the needle is at half you're looking at approximately 87-92 Celsius so right when the thermostat begins to open, and at 3/4 you're at 105-108 Celsius so just as the thermostat is fully opened.



Long story short... don't be worried if the needle on the temp gauge hits 3/4! Perfectly normal behavior and within the designed operating temperature. Knowing this made me feel a little better so I thought I'd share... Hope this is helpful!

My gauge has pretty much never gone over 1/2, but I don't have an automatic tranny either





My old Jeep used to creep up to just about 3/4.... then in 1 second it would shoot up to maximum, a CEL would come on and my engine would erupt in steam. lol, good times

I have to agree with Sugar.... When I had my Alpha the gauge never went over half...



The day it did I knew I had an issue that B-Man helped me out with in that there was mud in the cooling fins... So I sprayed high pressure water directly into the radiator and transmission cooler while the entire was running so it would help pull it out and wow - I ended up with a pile of mud under the front end that day... Back to normal.



Another potential problem is the thermostat may be toast or the wrong season.. don't forget there are several different ones..



But that Scan gauge you have is pretty kewl for keeping an exact eye on things...

Yup that's a good point and you should definitely be aware of other problems that could cause overheating. Mud is absolutely a big one... And like you say, not as easy as you'd think to clean the rad!!



More along the lines of heavy load on the motor (trailer towing, etc.) or driving in high heat with the A/C blasting, you'll definitely see the gauge creep up. For a vehicle that typically is steady at half this can be an OMG moment... But as long as you're 3/4 or less life is grand <img src='http://www.canadianhummerclub.com/forum ... ght_on.gif' class='bbc_emoticon' alt=':right_on:' />



Mine has only crept up twice.. once was MUD! And it was overheating pretty badly then... So that's not good but easy enough to correct and at least you know why. The other time was on vacation in stop and go traffic, A/C blasting and it was 35 degrees outside... It definitely hit 3/4 that day and I was a little scared I gotta say!

[quote name='JL' timestamp='1287768641' post='22007']

Yup that's a good point and you should definitely be aware of other problems that could cause overheating. Mud is absolutely a big one... And like you say, not as easy as you'd think to clean the rad!!



More along the lines of heavy load on the motor (trailer towing, etc.) or driving in high heat with the A/C blasting, you'll definitely see the gauge creep up. For a vehicle that typically is steady at half this can be an OMG moment... But as long as you're 3/4 or less life is grand <img src='http://www.canadianhummerclub.com/forum ... ght_on.gif' class='bbc_emoticon' alt=':right_on:' />



Mine has only crept up twice.. once was MUD! And it was overheating pretty badly then... So that's not good but easy enough to correct and at least you know why. The other time was on vacation in stop and go traffic, A/C blasting and it was 35 degrees outside... It definitely hit 3/4 that day and I was a little scared I gotta say!

[/quote]





U just got a hot little Humma!!!! <img src='http://www.canadianhummerclub.com/forum ... iggrin.gif' class='bbc_emoticon' alt='' />

Rhino runs normally at 1/2 but did get to 3/4 when on a warm day with a/c and on stretch of QEW that seems to cause higher operating temps. It also raised when Rhino was run at 150kph running down another member so we could convoy to an event.