How do you bleed the coolant system
Moderator: martauto
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MarkB
- E30 Zone Newbie

- Posts: 20
- Joined: Wed Jan 12, 2005 11:00 pm
- Location: Llanelli, South Wales
How do you bleed the coolant system on a 325 engine.
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Demlotcrew
- E30 Zone Team Member

- Posts: 13329
- Joined: Mon Dec 20, 2004 11:00 pm
- Location: East Anglia
There is a bleed screw on the thermostat housing.
You could also do a search!
Andrew
You could also do a search!
Andrew
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Rich_W
- E30 Zone Addict

- Posts: 2932
- Joined: Mon Jan 10, 2005 11:00 pm
The normal way. Start with a STONE COLD ENGINE
1) Heater to Hot (Yes I know - force of habit)
2) Pour in coolant to the max line, as it drops keep adding some in the correct mix
3) When the level appears to be stopping to drop. Squeeze all the rubber hoses gently. Which will help the air to circulate. Dont forget the heater matrix ones.
4) Top it back up to the max mark again
5) Repeat (3) a few times.
6) Leaving the Cap off the header tank Start the engine and allow it to idle. (might be worth getting a friend to start it)
7) Keep an eye on the level it might drop a bit on start up so make sure it doesnt empty the bottle as thats what draw air in.
Let it IDLE until the fan cuts in. You'll find that the hoses after the THERMOSTAT will remain cold for a while, but when it opens the water will flow into the radiator.
9) Wait till the fan stops then turn OFF the engine.
10) Do a final check on the level. Then replace the cap.
At NO TIME must the coolant reservoir run empty. Thats what causes most problems.
Thats the standard way. I have heard though that E30s in general can suffer from air locks. And that it can be helpfull to jack the front of the car up as high as possible (use axle stands please) Ive never needed to do this, but if you are having troubles then it might be worth considering.
1) Heater to Hot (Yes I know - force of habit)
2) Pour in coolant to the max line, as it drops keep adding some in the correct mix
3) When the level appears to be stopping to drop. Squeeze all the rubber hoses gently. Which will help the air to circulate. Dont forget the heater matrix ones.
4) Top it back up to the max mark again
5) Repeat (3) a few times.
6) Leaving the Cap off the header tank Start the engine and allow it to idle. (might be worth getting a friend to start it)
7) Keep an eye on the level it might drop a bit on start up so make sure it doesnt empty the bottle as thats what draw air in.
9) Wait till the fan stops then turn OFF the engine.
10) Do a final check on the level. Then replace the cap.
At NO TIME must the coolant reservoir run empty. Thats what causes most problems.
Thats the standard way. I have heard though that E30s in general can suffer from air locks. And that it can be helpfull to jack the front of the car up as high as possible (use axle stands please) Ive never needed to do this, but if you are having troubles then it might be worth considering.

