aridaen

Funny. I'm having this issue on my 86.5. It is doing the exact same thing as the OP posted. if I am driving, everything is fine, but when I stop and the car idles for any length of time, the temperature indicator goes up to the second line. The light doesn't come on, but today I was running the car while adjusting the audio amps and noticed the temperature needle at the second line. I shut the engine off, and then noticed water coming from the right side behind the front wheel like it was from the coolant tank. All the hoses in that area are new. I'm getting ready to replace the timing belt, and the radiator has corrosion around the bottom so I was going to replace that also just to be sure. I'll be replacing the water pump and all of the front hoses then too. I hope that will solve that issue and there's not something more serious lurking in there.

Mrmerlin

most probable leaking areas,
the heater control valve and short hose ,,
the right top of the radiator where the hot coolant enters,
and the water pump weep hole ,
and the hoses that attach to the water bridge or the radiator.
Best to replace the HCV and short hose the thermostat and the rear seal and O ring and coolant bottle cap

\ NOTE the coolant system holds about 16 sixteen liters of coolant,
8 coolant and 8 distilled water,
adding 4 liters is about a gallon

jp944s2

Hello,
I am having an issue with my 1987 S4 lately,
when driving normally with the AC on, the temp gauge is on the second level... when going uphill and pushing it, the gauge goes up towards the third level and the red warning light comes on even before it reaches the third level...
It never reaches the 4th red level though !!!

Fans are working perfectly... coolant level is fine...

Would greatly appreciate your opinions.