Bleeding cooling system

bmwhitman · 07-30-2012, 01:58 PM

I just recently topped up my coolant in my E90. Do I need to bleed the system? If so, how do I do that?

Surly73 · 07-30-2012, 02:11 PM

Quote:

Originally Posted by bmwhitman

I just recently topped up my coolant in my E90. Do I need to bleed the system? If so, how do I do that?

Hit START/STOP without starting the car, hold the throttle to the floor for 10 seconds.

(This is from memory but I think I got it right, it's in all of the DIYs

)

BKV122 · 07-31-2012, 07:37 AM

Quote:

Originally Posted by Surly73

Hit START/STOP without starting the car, hold the throttle to the floor for 10 seconds.

That but also have your heat on max temp (84f) and your fan speed on the lowest setting. Think the bleeding procedure last 12 mins.
Also theres a bleed screw next to your expansion tank cap, when filling/topping off your coolant you should have that open and ffill untill all air is done coming out of that bleeder screw hole and just coolant. Then close the bleed screw and do the bleed procedure stated above. If your battery is old its recommended to connect a battery charger.

bmwhitman · 07-31-2012, 11:46 AM

Quote:

Originally Posted by BKV122

That but also have your heat on max temp (84f) and your fan speed on the lowest setting. Think the bleeding procedure last 12 mins.
Also theres a bleed screw next to your expansion tank cap, when filling/topping off your coolant you should have that open and ffill untill all air is done coming out of that bleeder screw hole and just coolant. Then do the bleed procedure stated above. If your battery is old its recomended to connect a battery charger.

I only did a top up of about 1/2 a litre or less. What will happen if I don't go through with the bleeding procedure? Will the trapped air cause problems in the coolant tank?

raceyBMW · 07-31-2012, 01:22 PM

Trapped air can cause a number of issues, the biggest one is overheating. If you only topped off, and didn't pull the drain plug, then there is no reason to worry about air in the system. Opening the expansion tank lid will not introduce air.

bmwhitman · 07-31-2012, 02:32 PM

Quote:

Originally Posted by raceyBMW

Trapped air can cause a number of issues, the biggest one is overheating. If you only topped off, and didn't pull the drain plug, then there is no reason to worry about air in the system. Opening the expansion tank lid will not introduce air.

Music to my ears. That's all I wanted to hear. You guys are awesome!

07-30-2012, 01:58 PM	#1
bmwhitman Private First Class 52 Rep 178 Posts Drives: E90 Join Date: Aug 2011 Location: Toronto iTrader: (0) Garage List 2025 BMW G80 M3 Com ... [0.00] 2006 BMW 330i (E90) [0.00]	Bleeding cooling system I just recently topped up my coolant in my E90. Do I need to bleed the system? If so, how do I do that?
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07-31-2012, 01:22 PM	#5
raceyBMW king of the hills 114 Rep 2,923 Posts Drives: 2011 M3 w/ESS55, 2001 540i/6 Join Date: Dec 2006 Location: Arvada, CO iTrader: (1) Garage List 2001 BMW 540i/6 [8.17] 1994 530i [9.00] 2007 335i Coupe [8.37]	Trapped air can cause a number of issues, the biggest one is overheating. If you only topped off, and didn't pull the drain plug, then there is no reason to worry about air in the system. Opening the expansion tank lid will not introduce air.
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