Hey e36 crew. My OBC tells me occasionally that I should check my coolant level when I turn the ignition off. I've checked it when cold and it's dead on the "Cold" line. Sometimes the warning comes on, sometimes it doesn't. I remember having the same warning come on about 6 months ago and I added about 100mL of fluid and it went away.
Is it just that I'm on the edge of when the sensor goes off? Is it possible to have a leak so slow that the system loses 100mL over 6 months?!?
Hi tehskeo, I would first try and add a little bit of coolant and see if the warning goes away. And if you really want to see if there is a small leak in your system, you can always do a system pressure test to be sure.
^ this would be my guess. Same thing happened to my car - the wire at the connector was starting to go... sometimes it would work, othertimes not until it eventually failed completely and the warning was on all the time.