Emptying/changing coolant

mcbutler · Post by **mcbutler** » Mon Nov 21, 2022 9:18 am

few months ago my coolant filler cap came off whilst driving, lost a lot of coolant but did not overheat and no damage done in the long term.
I had to top up the coolant with boiling water immediately whilst the car was in coolant priming mode.
So today car is in storage and my mind turns to the reduced anti freeze concentration, coolant swap required.
I plan to let the water pump do the draining for me, pop the recirc hose off the header tank and connect it to a bucket, coolant prime mode and off we go.

So question is does anyone know any reason why this will not work? I know it wont completely empty the block but worth a try i think..

Thoughts guys??

flybobbie · Post by **flybobbie** » Mon Nov 21, 2022 10:27 am

Why not just do it properly and be done with.

Chippie · Post by **Chippie** » Mon Nov 21, 2022 10:32 am

I can’t see any reason for it not to remove enough water to then top back up with neat antifreeze, I think there can be some incompatibility with certain types of antifreeze, so I’d suggest probably buying it from BMW, also make sure the battery is fully charged and possibly even keep it on a battery charger while the pump is running and turn the ignition off once water stops flowing so you don’t burn out the pump, although it probably wouldn’t anyway.

grannyknot · Post by **grannyknot** » Mon Nov 21, 2022 12:58 pm

You can pick up a coolant tester for a few bucks and measure the temp that your current coolant is good for.

mcbutler · Post by **mcbutler** » Tue Nov 22, 2022 9:42 pm

grannyknot wrote: ↑Mon Nov 21, 2022 12:58 pm You can pick up a coolant tester for a few bucks and measure the temp that your current coolant is good for.

Yeah I have one of those, thats really going old school, will test it anyway..

mcbutler · Post by **mcbutler** » Tue Nov 22, 2022 9:44 pm

Chippie wrote: ↑Mon Nov 21, 2022 10:32 am I can’t see any reason for it not to remove enough water to then top back up with neat antifreeze, I think there can be some incompatibility with certain types of antifreeze, so I’d suggest probably buying it from BMW, also make sure the battery is fully charged and possibly even keep it on a battery charger while the pump is running and turn the ignition off once water stops flowing so you don’t burn out the pump, although it probably wouldn’t anyway.

Cheers Chippie some good tips there, battery charger is a must I think so going to go ahead with it.
No point dtruggling doing it the 'right way' as some suggest. Thinking outside the box generally works better than 'sheeping' it.
will update once done

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