stenakt

My temp gauge is reading off the scale (hot) most of the time. When its not, it reads normal. The engine appears to be running at normal temp so I guess its the gauge (tried a new sender unit which didn't fix it).

Can I fix this myself or does it need to be sent off for some boffins to fix?

thanks chaps.
oh my poor head

Dan Shea

I'd check the thermostat, it could be sticking. Which would cause the temps to raise on occasion.

quinnfiske

You might also have an air bubble in the cooling system. When you take any of it apart it is important to bleed the air out of it. There is a bleed port at the front of the engine (takes a 12mm wrench). Do a seach to find many threads on this topic.

JimV8

Toronto eh. I have a remote infrared sensor to read temp so why not drop by the GTA get together on Saturday and I could take a reading ( go to all forums and click on Canada). You really don't want to be running off the scale though. If the temp reads normal some times and at other time hot it could be anumber of things. Do both fans come on when it gets hot?

fpena944

Check your grounds. I had the same problem too but it was intermittent.

Lemming

If you tap the plastic in front of the guage when it's pegged, will it return to normal?

ausgeflippt951

This is actually not very plausible, given the respective thermal conductivities of both water and air. If there were an air bubble, you'd be seeing a lower temp than actual.

NCporsche

If you need to cool the water down, try turning on the air conditioner. Turning on the A/C activates the fans which pulls more air through the radiator. My '86 944 runs close to the top, in the summer and at high revs (autocrossing). I turn the A/C on and the temp returns to normal, or at least close to normal.

ausgeflippt951

Given that you live in Toronto, you prolly don't have this problem, but running water wetter helps lower all-around temps; I'll be throwing some in my rad in a bit. Then again, I live in Tucson...

fpena944

I could hit the top of the dash and it would at times return to normal. Do you think it might be something else?

UncleMaz

Air pockets can cause the thermostat to function incorrectly/not at all. Bleed the system before you do anything else. These cars don't have the fill and forget it feature. ONce you open that closed system, the system WILL need to be bled.

Lemming

I don't believe that you have anything wrong with your cooling system, instead you likely have bad connections at the guage end. Pull you cluster and check for good connections and clean you grounds. I am currently having the exact same problem with my 986 daily driver; but I'm too lazy to fix it.

UncleMaz

There is always the possibility, err, liklihood of wonky VDO gauges.

stenakt

I think you're on the right tack - the gauge flickers (rather than rising slowly), so its not overheating, rather an instrumentaion problem. I tried tapping the gauge as suggested and it dropped for a little while then went up again instantly. I'll try pulling the dash and have a poke around, although I'm pretty lazy too.

stenakt

thanks for the offer Woodie, but I'm pretty sure its not a temp problem. You a PCA UCR member?