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View Full Version : Bleeding cooling system on E39?


Redster
03-29-2008, 10:32 PM
Would this be accurate/best way to bleed cooling system on E39? The car has been sitting in the garage for a while and when I took it for a drive a hose cracked, I changed it and added coolant but now there's some air stuck in there..

Procedure I found on bimmer forum:

turn the key to the on position but with the car off. turn on the heat as high as it will go, but set the blower to the lowest setting. with the res tank cap on, and the bleeder screw open, wait for air bubbles to stop coming out of the bleeder screw and just straight liquid. close the bleeder screw, your system is now bleed. the high heat and low blower setting turns on the secondary water pump which cycles the system (you will hear it running). IIIRC the total capacity is either 3 or 4 gallons, but Im pretty sure it is 3 gallons.

Oyster
03-29-2008, 10:36 PM
I usually do it with engine on, heater on,

make sure you use the BMW dealer fluid. Should be blue color. Avoid the prestone shit

Redster
03-29-2008, 10:38 PM
I don't care how, whatever works the best..so feel free to suggest anything:)

BmW1819
03-30-2008, 12:11 AM
there is a bleeder on the resisvoir or on the thermostat housing

Redster
03-30-2008, 12:30 AM
Yes I know where it is (overflow tank), I'm just asking what's the best/fastest way to do it.

chromius
03-30-2008, 11:20 AM
IMO, bleeding it with the engine off never seems to get all the air out. The Aux pump just doesn't circulate fast enough.

Personally I will fill it up as much as possible with the engine off, then run the engine with the heater on max and rev the engine a couple of times, shut off, recheck level, repeat until it no longer requires topping up. Only run for short bursts though so the coolant doesn't heat up. This procedure is outlined in the BMW TIS...I'll try and dig it up.

chromius
03-30-2008, 11:35 AM
here it is...

Redster
03-30-2008, 01:37 PM
Thank you!

BmW1819
03-30-2008, 05:39 PM
the way we bleed is open bleeder screw and poor coolant till coolant comes out
run car with heater on and crack the bleed when the car hits full temp to let all the air out u can do it a couple of times