bstens

Hello. I have a 2001 A4 1.8 Quattro. While changing the upstream 02 sensor, I moved the coolant expansion tank to the side w/o removing it completely. It rested on its side for a bit while I worked.

Immediately after starting the vehicle the coolant light began flashing and has not stopped. The levels look normal, no apparent dripping, and everything is in place.

Could I have jarred something when working on the o2 sensor? Is it safe to drive?

Thoughts? Thank you.

Huskerbob

Plug the sensor back in to the bottom of the tank.

bstens

Thank you for your response. I don't think I unplugged anything from the tank. I only removed the screws that hold the tank in place.
I'm not a very experienced AUDI DIYer so perhaps I unplugged a sensor without realizing it. Could you give me some more detail about the coolant sensor?

Thank you very much.

Articus

The coolant sensor is hooked into the bottom of the coolant tank. It's possible it was loosened when you lifted the tank out of it s place. It's easy to locate. Lift the tank up. There are rubber hoses going into the tank and then 1 connection that is not a rubber hose. that is the coolant level sensor. just pull it out (i forget if it has the VAG connector thing you have to press) and push it back in. While you are there, make sure there is not coolant leaking from that connection spot also which could also cause trouble

bstens

Thanks.