Coolant light on briefly, however coolant level appears fine.

[nsk040]

Getting a bit colder so this all may actually have coincided with having the heat on for the first time in many months. The coolant light came on briefly (~60 seconds) and then went away a few days ago. Same situation today.

I checked the level after the car had cooled off and the floating gauge pops right to the top so doesn't appear low. I'm aware there is a bleed screw of sorts right by the coolant cap, so do I need to open that up to get a true read of coolant level?

Thanks

[danewilson77]

Whatever you do... No over filling.

Sent by the Pixel XL

[fredo]

I had the same symptoms last year. My Indy replaced the expansion tank and that was the fix. He said there's a sensor in the unit, and it failed.

[BMWCurves]

I had the same symptoms last year. My Indy replaced the expansion tank and that was the fix. He said there's a sensor in the unit, and it failed.

I'm pretty sure the sensor is separate from the tank itself. You should be able to replace just the sensor, but you'll have to drain your coolant since it's in the bottom of the tank.

[anandoc]

I'm pretty sure the sensor is separate from the tank itself. You should be able to replace just the sensor, but you'll have to drain your coolant since it's in the bottom of the tank.

Can confirm, the sensor just plugs into the bottom of the expansion tank and it is a separate part. Part# 17137553919.

[Vas]

Last time the cooling system was replaced? Might be time to do a basic overhaul of it before winter.

[Aeternalis]

Mine does this since the temperature has dropped. My entire cooling system was replaced in February, so I was skeptical that anything was amiss since I haven't seen any spots or puddles under my car.

I suspect that my system wasn't filled or bled properly according to the info here:

http://www.bimmerforums.com/forum/showthread.php?1957138-DIY-intermittent-coolant-level-light-fix-E46

Being that it's just a light and doesn't stay on for very long, I've let it be until I have enough time to dedicate to fixing it.