Pyzik

Hey guys, I haven't drove my car for about a week and yesterday I started it and my temp light came on after like 10 sec and temp needle was at cold, car runs rough for maybe 5min then its perfect. Light stays on. Temp needle goes to 1/4 on temp gauge and stops, (that's where it usually stopped)
some popping in plenums in the warm up . What could it be?would the rough idle warm up be related to the temp sensor?

G8RB8

Check coolant level. I think it's the same light.

Pyzik

Coolant is fine,

Pyzik

Would a bad temp sensor the one on top of engine by thermostat(it has 2 wires ) couse that?

jeff spahn

Pictures of your car please, your headlights in the avatar look interesting to say the least.

neilh

Coolant temp warning light has a thermometer symbol, low coolant is the words' COOLANT" on a pre S4, which this appears to be ( Pre 86.5 anyway) . Check the wiring from the temp sensor to the 14 pin plug - most likely frayed, burnt or shorted
Pin out of 14 pin is attached. Check wires at pins 3 and 5. Sensor could also be bad.

Pyzik

Hey Neil, what am I checking for ? Resistance? Continuity?

Pyzik

I have a the s3 928, 85/86