No heat after coolant expansion replacement M54

rwm514 · #1 08-06-2019, 12:35 PM

So as the title says, I recently replaced my GF's coolant expansion tank. When I refilled the coolant, I noticed that it wouldn't take additional coolant once I turned on the heat inside the car and ran the fan on low. I tried running it to warm about 10 times to see if it would drop coolant level but it never did and still won't blow warm air. Any ideas?

Background: It had a slow leak from a crack in the expansion tank and actually ran hot on the gauge cluster. She shut it down immediately and had it towed to my house. I believe it was pretty low on coolant which caused the high temp. I also replaced the main thermostat, the thermostat in the bottom of the expansion tank, a new sensor in the tank and the other sensor in the lower radiator hose as well as a new cap on the tank.

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wpoll · #2 08-06-2019, 05:21 PM

Did you bleed the coolant using the proper method? Filling the system with ignition on but engine not running? This runs the electric aux water pump - you can see the small stream of coolant coming back into the top of the expansion tanks when its getting full.

rwm514 · #3 08-06-2019, 06:01 PM

Yes. That's how I did it but the level didn't drop at all when I put the ignition in position two and turned on the heater.

wpoll · #4 08-06-2019, 06:29 PM

Quote:

Originally Posted by rwm514

Yes. That's how I did it but the level didn't drop at all when I put the ignition in position two and turned on the heater.

Did you hear the aux water pump running or see the small stream or returning coolant? Maybe the aux water pump has failed.

There's also a couple of bleed screws you need to open but that's before you turn on the ignition - when you're doing the initial fill. Cover the alternator with a plastic bag to avoid screwing it with coolant....