Noticed a small issue just now, (1990 L series, carby) As my revs rise the water temp gauge is rising as well, more prevalent at about 3000rpm+ (don't have a tacho so can't say for sure). Normally runs at 1/3rd on the gauge, as soon as I rev higher it moves to about 2/3rds up. If I let the car idle straight after revving or pop it in neutral while driving it just goes back to normal operating temp. I have replace the water temp sensor on the top left side of the block about 2 months ago so doubt that would be faulty & car is still way to hot at the moment to check coolant/oil etc. Car doesn't seem to be driving any worse than normal for a EA82 & no other obvious symptoms of a blown head gasket.

 

If it was the car overheating I doubt it would go down as soon as the revs drop but I don't really know.

 

Happened to anyone else before?

Does the temp drop when you start moving faster, like on the freeway? Or when you come to a stop, does the temp go up? Or is it strictly rpm related?

 

You said you replaced the water temp sensor, did you replace it with the dealer one or one from some auto parts chain? I believe everyone says to use the dealer only part for that, as ALL the other ones tend to fail for some reason or another. That and the dealer part is not anymore expensive.

Moves up & down with revs while driving otherwise it's at the normal temp, doesn't go up when at a standstill. Seems to be rpm related.

 

It's from an apparently good aftermarket company over here in Aus...our dealer parts would be about 5x the cost & I wouldn't be suprised if there were none available.

Ahh, your in Aus... Your location said WA, so I assumed your parts would cost the same as me, since I live in WA.

 

I would still suspect the temp sensor... Wait, are we talking about the same thing? I am referring to the THERMOSTAT, not the sensor, my bad! :-p So before I continue, lets make sure we are on the same page

Nope, sensor...from what I cant tell it just gives the gauge a reading.

Well then, I would try to get an actual reading of the temp of the car. You need a baseline to see if the gauge is actually reading correctly. If it is reading correctly then you have a different issue than if it is not reading correctly. So get an actual reading of the engine temp, and then go from there.

Coolant levels & colour all good. Oil full & appears all good.

Have you temped the motor yet? No use doing anything else until you know what the motor temp actually is...

Check your alt output as the voltage flux can cause this. Also if your electric fan is dying and drawing too much current.

 

I had this with a digital dash, i imagine it could happen with an analog as that is the only thig that changes that quickly with engine rpm. Even a coolant fault wouldnt respond that fast.