525i cooling

[nickandben]

2 weeks ago renewed coolant, bleed system again again, but low coolant warning still showing on dash, any idea guys, thanks

[bimmerd00d]

i did too, replace coolant level sensor. I'm going downstairs to do this myself

[nickandben]

i did too, replace coolant level sensor. I'm going downstairs to do this myself
how?

[BMWfreak]

About a month ago I changed t. belt, water pump and all the related cooling crap and even though the coolant level is OK I get the "Coolant Level" message on OBC. How hard is it to change the sensor yourself ??? Could it be only disconected sensor wire at the bottom ???

[Russell]

Not too hard on a M50 engine. Remove the sensor wire and remove the large plastic nut to remove the sensor. Be prepared to drain at least 1 gallon of coolant out. Most from the expansion tank on the M50. Make sure the engine is cold. Screw in new sensor and tighten. be careful and not over tighten. I had trouble finding a wrench that fit. Not much space. I used a pair of slip joint type plyers. Had a slight leak at first. it stopped.

Refill the coolant. You may need to bleed the cooling system several times to get air out. Open the bleed screw on top of the radiator while the engine is running, let it warm up with the radiator cap on, and release air until coolant runs out, then close the bleed screw. Make sure the heater is full on for coolant circulation.

Unfortunately, I still have the cooling level message most (but not all) of the time. I think it is electrical. I plan to check the wiring under from the connector back. I also plan to clean connectors on my instrument cluster. I have heard there could be an issue with the cluster causing this type problem. Not proven.

I am not sure how the sensor really works. When the sensor message is displayed, I think it means there is an electrical "open" vs a closed circuit with the message not displayed. Not sure?



About a month ago I changed t. belt, water pump and all the related cooling crap and even though the coolant level is OK I get the "Coolant Level" message on OBC. How hard is it to change the sensor yourself ??? Could it be only disconected sensor wire at the bottom ???

[BMWfreak]

Is it similar in M20 engine ???