Jeff Doble

I bought an 86 4ks a little while ago as a daily driver and it's my first German car so I'm a little naive to it's quirks.

Anyhow, the car runs well on the highway until I get stuck in traffic and am crawling along or stopped for extended periods of time. A minute or two after coming to a stop the water temp needle starts climbing towards the top of the gauge until it gets about 3/4 of the way up. Then, it sort of hoovers there while the fan cycles on and off. After getting back up to speed, the needle falls back down to the middle of the guage and stays there. I haven't been stuck in traffic for more than 15 minutes or so but having never seen a temp needle swing up that high makes me nervous. Is this what the car should normally do. All the fluids look fine and the radiator was replaced within the last couple of months by the previous owner so there aren't any clogs in it.

Ken 4000

replace/look at the over flow unit (coolant expansion tank), i had the same problem and i turned out to be that thing, its right next to the water/cleaner holder for the wipers, i don't know what was wrong with it i just changed it and it didnt overheat on me anymore

eharleq

It's not overheating, just cycling. The overflow does suck badly, but maybe you replaced the temp sensor that pugs into the base? That was the problem most likely.

I have exactly the same cycling and it seems right for the car. There is a three position switch available.

Jeff Doble

Thanks

Ken 4000

no mine was over heating white cloud subtances coming from my car led me to that conclusion.

eharleq

I wasn't disagreeing with you...The other behaviour is normal.