My temp gauge jumps to the midpoint about 30 seconds after I start my truck, which can’t be accurate; it was 15 degrees outside this morning! Anyway, do you think the gauge sending unit could be the culprit or the gauge itself? My truck is an 88 3.0 with full gauges by the way.

 

My bet is sending unit or wiring.

:wabbit2:

 

X2 on sending unit or wiring, as the gauges usually do not have issues.

 

I have the exact same issue, but became too lazy to look into it. I have an '88 4Runner with a 22RE, equipped with a 3.0 gauge cluster though (was free)...

 

Calling Autozone now to see if they have a sender, I just replaced the hoses, thermostat, radiator and the coolant temp sensor for the ECU so this sender would be just about everything! Ill let you know if it fixes it...

 

Ive had the temp sending unit go bad and cause the gauge to read some times or not at all.

 

No luck, I put a new sending unit in and it now it still jumps right to the center of the gauge... Any ideas? The connection had never been apart and was still clean so I doubt its wire related.

 

Check your ground to the instrument cluster, might be another possibltiy then. Do you have another gauge to try?