Hi

I hope you don't mind the question.

I had to replace the expansion tank on my 03 4.4v8 the other day as it split down the side.

I've replaced the tank and put a lower pressure cap on it (as per recommended on here and other forums), but I am having trouble bleeding it all.

As it stands now, I've just been out to have a go again and when hawkeye gets up to about 103 deg, coolant spews out of the rear outlet on the expansion tank. I've tried loosening the bleed screw to eliminate air, which it has done, but I seem to be in a vicious cycle of not enough fluid, topping it up then when its up to temperature it coming out of the back again. Its clearly got an air lock because the bottom hose is pretty cold and the top is hot, and the cabin heater is working fine.

Concerned there may be a Head gasket fault or similar, the oil level is fine and a proper colour and the coolant/water I've been putting in is crystal clear, as is exhaust output and oil cap is free of mayo.

Is there any golden advice to getting this bled correctly?

Cheers

neil. 2010 L322 Autobiography Black Edition
1975 Land Rover

The best way I found was to back full the system using a hose I pulled one of the heater hoses off poked the hose up it and ran low pressure water threw it leaving the expansion cap off and letting the excess air escape from there refitted the heater hose and ran it up again with the cap off until no more air.
Job done !

Thanks GSXR.

I might give that a go - I don't know why but I always seem to struggle bleeding coolant with cars and bmw's seem no exception.

I've read the fairly indepth procedure on some of the BMW forums on the v8...still struggled. 2010 L322 Autobiography Black Edition
1975 Land Rover

It works for me...the official guide didn't iv a mechanic mate who's rebuilt a few of these and he blows down small return pipe from the rad

I’ve had success in jacking up the front of the car while trying to bleed, I read it somewhere that BMW’s appreciate it while bleeding... ______________________________
Simon
______________________________

Range Rover Classic 3.5 efi - Gone
Range Rover Classic 3.9 efi - Gone
Range Rover Classic 4.2 LSE - Sadly gone
Land Rover 110 3.5 - Gone
Range Rover P38a 4.0 SE - Pleased it's gone
Range Rover P38a 2.5 DHSE - Just sold
Range Rover L322 4.4 v8 Petrol - Current

It is well understood that BMW's all benefit from the front being as high as possible when bleeding. It keeps the expansion tank up in the air and allows garvity to assist the bleed.

e39's and e53's were certainly a case in point.

I make Simon correct. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner