Aafraid of overheating after new coolant sensor!!

[Russell]

I just replaceed my coolant sensor on my 95 525i. drained at least a gallon of coolant out of tank and radiator.

refilled expansion tank with about 1/2 gallon or so of coolant, started engine, put heater on high and waited to bleed and add more coolant. Radiator never did warm up. Coolant level in expansion tank did not drop. opened bleed screw amd pumped hoses. did not help. Have not driven car.

After temperature went just over half way I turned car off. afraid It will overheat. Hope it did not damage waterpump or thermostat?

What do I do next?

[kiNGMak]

*** Bump ***

[Anton CH.]

So did any liquid come out of the bleed screw location, did gargle a bit?

[Russell]

After, I let it cool down, the expansion tank coolant level was low, I lossened the bleed screw and added coolant. As I added coolant, it seemed to be pulled into the radiator. I filled it as full as possible and let it run and let air come out the bleed screw. Interestingly, at this point no warm air from the heater until I drove the car around the block. Later, I drove the car on an errand and no overheating issue. I will continue to bleed until I am sure the coolant level is correct.

However, I still get the coolant sensor light even with a new sensor. I suspect the issue is electrical. Perhaps the instrument cluster board, as Bill H has suggested, has a bad connection.

Thanks for your help

So did any liquid come out of the bleed screw location, did gargle a bit?

[ryan roopnarine]

ie temperature gauge is at a point that would normally produce warm air, and you don't get warm air out of the vent you need to keep bleeding, as there is an airlock somewhere. if its being as stubborn as you say it is, one way my unkle showed me how to bleed it was to disconnect one of the hoses from the firewall to the heater control valve, and start the car with the heat on. keep the hose off until a significant amount of water begins to flow out, as in the situation you describe, there should be no water coming out if no heat is being produced. shut the car off until you have reattached the hose well. start it up again and see if you get heat, as you should. at that point, you can shut off and and bleed and replace any that might have been consumed.

[Russell]

Think I am ok now- got heat. Thanks.