Help! Air in the cooling system, bleed doesn't work

[Unregistered]

I have a 1990 525i with the radiator and h2o pump replaced last year.

I get a coolant level indicator on. When the engine is hot and I open the radiator cap (a "no no"!), the level is 5 inches below the cold fill level but then it quickly fills up 4 inches above cold level line on the expansion tank with a slurping / gurgling sound.

I bleed all the air out with the engine off, only coolant come out the bleed hole at running temperature.

What is wrong and what can I do?

"Let it Bleed"
Littlematchgirl in Czechago, Illinois

[TimGinCentralNJ]

...I believe it states you should check your coolant levels while the motor is cold (this also beats getting an unexpected 220+ degree power-shower). You should start your car, move the heat/defrost control to "max", then open the coolant resevoir. Slowly add coolant to the "MAX COLD" line on the resevoir, then cap it. Open the bleed screw and rev the engine a little. (You can also squeeze your primary hoses too to get air out, but watch out, they get hot once the motor warms up). You will see a lot of air escaping, but you'll start to see it mixed with coolant. Keep doing this until only coolant comes out. You may need to do this a few times, too.

Hope that helps,
Tim G.
'91 535iM


I have a 1990 525i with the radiator and h2o pump replaced last year.

I get a coolant level indicator on. When the engine is hot and I open the radiator cap (a "no no"!), the level is 5 inches below the cold fill level but then it quickly fills up 4 inches above cold level line on the expansion tank with a slurping / gurgling sound.

I bleed all the air out with the engine off, only coolant come out the bleed hole at running temperature.

What is wrong and what can I do?

"Let it Bleed"
Littlematchgirl in Czechago, Illinois

[Tiger]

When engine is cold or warm and radiator cap off... I simply grab the upper radiator hose and squeeze repeatedly until it is filled with coolant... This works on most cars.

[zmuff]

In addition to Tiger and Tim's recommendations, I raise the front right side of the car a few inches to create a high point for trapped air to go to. Never had a problem with bleeding.

[silver-e34]

i disconnect the top radiator hose and add water to the radiator till it spills out the hose then bleed it after it warms up just to make sure its all out. it works everytime

[Unregistered]

Thanks Muff, Silver and everyone else for your excellent advice. Seems obvious, but I have never learned how to correctly bleed my cooling system. Maybe my public school education, I did see some nasty scare flicks in Drivers Ed!

Jason

[ryan roopnarine]

if this happens only when very warm or hot, there is no air in your system...the level is supposed to rise rapidly like that when the car is hot....for the same reason coolant will explode out if you open the cap when hot..if the bleeder is discharging only coolant, and no bubbles, there likely isn't air in there.


I have a 1990 525i with the radiator and h2o pump replaced last year.

I get a coolant level indicator on. When the engine is hot and I open the radiator cap (a "no no"!), the level is 5 inches below the cold fill level but then it quickly fills up 4 inches above cold level line on the expansion tank with a slurping / gurgling sound.

I bleed all the air out with the engine off, only coolant come out the bleed hole at running temperature.

What is wrong and what can I do?

"Let it Bleed"
Littlematchgirl in Czechago, Illinois