Temperature Guage not working?
 

O.K. - I have been all over the map on this - my car (87 911) seems to get to about 100 - 110 Celsius before the external thermostat to the fron cooler opens. I have replaced the oil feed lines to the front cooler with Elephant Racing finned lines as one of the lines was a bit crushed. This made no difference in my temps, so I pulled the front cooler t-stat and it appeared a bit sticky. I bought a new one from out host and just installed it. Using the idle in the driveway test, my gauge temp gets almost to 9 o'clock before the external t-stat opens and oil starts to flow to the front cooler. Once it starts, it flows fast and hard and both lines and the front cooler heat up nicely.

Thinking I needed a second opinion on the actual oil temps I used my handy dandy meat thermometer and lowered it on a wire into the oil fill tube - the temps there read about 180 F (which is 83 Celsius - the poitn where the external T-stat should open). Placing the same thermometer on the T-stat housing I saw about the same temp and saw about 190 F on the lower valve covers.

So - is my temp gauge in the dash broken? If so, how do I fix it (or test it). This is really pissing me off.

Thanks for any help.

Well I was leafing through my 101 Projects book and came across the prject for replaing the oil temp sender unit and upgrading to a numerical dash gauge - I think I will give that a try.

I replaced mine last week and it's nice to know that the set is somewhat calibrated and you can trust it.