Temp Gauge hitting red

[upstaterick]

The temp gauge in my 94 (3.0 engine) goes into the red when climbing hills. Other than the gauge showing overheating there is no visible sign this is happening.

I had it into my mechanic today, he tested for blown head gasket, etc. Everything checked out fine. The vehicle runs fine, no smoke no water in exhaust etc.

He was doing a coolant temp test when I went there afterwork and the temp the gauge showed differed by several degrees from what the thermometer in the radiator said.

What could be causing the gauge problem and is the vehicle truly not overheating or just not showing the typical signs of overheating? I'm baffled and now afraid to take it on any lengthy trips until the problem or lack there of is fixed.

 

[hossmaster]

You might want to check the ground or grounds off of that gauge and where it hooks up. Sometimes a bad ground might throw a higher than normal reading. Or the gauge is going south. Its not using coolant or boiling in the reserve tank?

 

[upstaterick]

It's not losing coolant or boiling over in the reserve tank.

I noticed this morning that the gauge climbs from dead cold to full operating temp in less than a mile to work at 30mph. Seems to me the gauge should barely show warmed up in that short of a distance.

 

[hossmaster]

Yea I would try to find some wiring diagrams and maybe chase down the grounds and see if they are making good contact.

 

[mikes4runner]

Mine will show warm quick too. from the far left to the middle thats normal.....but mine does not go into the red. I can say that the gauges suck and are not the most accurate look at your oil pressure gauge while idling when warm you would think there was no pressure. maybe the temp sending unit.


Mike