Coolant drain and refill

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johnwindwood
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Post Mon Aug 08, 2016 1:52 pm

Guys

My Son's 320 needs a coolant change. Is there a specific way to refill the system or any need to bleed it? Any tips appreciated.
Thanks.
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aimlessrock
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Location: Manchester

Post Mon Aug 08, 2016 1:55 pm

a vacuum bleeder would be a worth investment if your keeping the car, not expensive and saves lot of time :D
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
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Brianmoooore
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Post Mon Aug 08, 2016 2:10 pm

Make sure the car is level at least, and preferably facing slightly uphill. Open the vent on the thermostat elbow, ensure that it isn't blocked, add the coolant slowly until coolant comes from the vent, close the vent, and fill the header tank.
Set the heater to full hot, the fan to full, and the slider to the footwell.
Start the engine, and ensure that, after a minute or so, warm air can be felt coming from the heater. Watch the temp. gauge at the same time.
If no heat is felt, and the gauge starts to head towards the red, you have an airlock in the cylinder head. Easiest way to deal with this is to fill the header tank to the top, remove the top heater hose on the bulkhead, and then refit it, while coolant is flowing from both the hose and the stub pipe.
Small amounts of air will be ejected into the header tank over the next couple of days, so keep an eye on the level, which should be at the horizontal seam of the tank, but in my experience settles about 10mm - 15mm below this.
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johnwindwood
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Post Mon Aug 08, 2016 2:56 pm

That's great-many thanks :)