Temp Gauge jumping

[matt_spoon]

i noticed today when i left to go to dinner that as my car warmed up the temp gauge would jump up towards the red but it would usually jump right back to the middle. it was a very quick jump forward then it would drop right back into place and it didn't climb towards the red consistantly, just jumped.

any suggestions on what this may be? temp sender unit? Bad Cluster?

btw, i checked the coolant level and it's normal.

[E30SRPower]

Mine does that too. Pisses me off pretty good.

I don't know why it would do it. The ECT sensor usually is a temperature sensative variable resistor. IT modifies the input voltage and sends it to thegauge to register your coolant temp. Most stock ones in japaneese cars suck. they are basically 3 position. I don't know how accurate german ones are.

Joey

[arsevader]

Classic signs of the nut on the back of the gauge being loose or dirty.

Remove the instrument panel and clean the nut up and tighten it back down. This nut provides the ground for the gauge and causes the problems you describe.

James

[E30SRPower]

Awesome! thanks a bundle James!

Joey

[Nathan]

If it is the nut on the back doesn't it jump to cold not to hot? Would it make more sense that there is a short somewhere cuasing the temp guage to jump up? Just my logic on the situation. Had this problem with mine but with jumping to cold and it was the nut.

[parkerbink]

Mine did this when the monkey (no offense meant to monkeys) that fixed it left the ground strap that goes from the frame to the motor on the oil pump side left it off. I put it back and all was well. Check your grounds.

[arsevader]

If it is the nut on the back doesn't it jump to cold not to hot? Would it make more sense that there is a short somewhere cuasing the temp guage to jump up? Just my logic on the situation. Had this problem with mine but with jumping to cold and it was the nut.

It can do either. Bad grounds cause all kinds of problems.

James