1986 Audi 80 B2 1.8 Coolant temperature sensor

[Deadchemist]

Hi everyone!

 

Had an issue with the temp gauge showing I was getting hotter than usual last week. Always run flat at 90c but last week was running above the 90c and spiking to the line above.

 

Went and checked the bottom hose and low and behold was stone cold so did a full flush and switched the thermostat. Since then the temp gauge is still reading hotter than usual. Checked the pipes with a thermo gun and they were running at 90c, bottom hose gets hot, thermo opens and fan comes on.

 

The issue is the gauge is still reading hot, casual driving around it sits at above 90c and fluctuatea between the first line above 90 and just above 90.

 

I've read and re-read the Haynes but I can't seem to find where the coolant temp switch lives. There is Nothing on the flange that comes out of the side of the head and only the thermostatic switch on the front (which controls the manifold pre-heater/auto-choke for the pierburg 2e2).

 

I've ordered a new temp coolant sensor but not much point until I can see where it goes! Also, the gauge is behaving totally as it should do in the sense it slowly gets up to temp. I've bleed all the air out by massaging the hoses/jacking up the expansion tank point and there is no more air coming out

 

Any help would be greatly appreciated!

[Deadchemist]

Thanks!