Bleeding the cooling system on a M50 -Help?

[oldroydsr4]

Hi Everyone,

Having a nightmare bleeding the cooling system on the m50 after changing the thermostat and waterpump.

And after a little advice.

How long should i run the engine before the heater becomes hot?
(It got just over half way on the temp gauge and i turned it off as I didn't want to do any damage).

The tophose is hot but the bottom hose is stone cold.

The pipes going into the heater matrix felt hot but the heater hadn't produced warm air.

Any help or steps by step advicewouldbe much appreciated.



Cheers in advance.

[E30BeemerLad]

Defo got the rear pipes connected correctly dude?

I had a bit of chew getting mine to produce hot air to start with and it was a bit of a game of temp gauge bingo. I did end up with the front end in the air in the end and pulling the top hose off the rad, loosening the clip that goes to the thermostat and rotating the hose so that it was easy to fill from the hose direct into the block until water starts coming out of the rad top outlet, then refit the hose and bish bosh.

[Alpina99]

Have you got a bleed screw built into the top of the rad ?

If so, try undoing this slightly to vent any air until water starts seeping out,

This cleared a major air lock on my E34 with an M50,

Worth a try,

[oldroydsr4]

Defo got the rear pipes connected correctly dude?

I had a bit of chew getting mine to produce hot air to start with and it was a bit of a game of temp gauge bingo. I did end up with the front end in the air in the end and pulling the top hose off the rad, loosening the clip that goes to the thermostat and rotating the hose so that it was easy to fill from the hose direct into the block until water starts coming out of the rad top outlet, then refit the hose and bish bosh.

I hope I've got the pipes to the heater valve the right way , I've only just replaced the valve and doing up the jubilee clips is a nightmare.

I'll double check the hoses to the heater, jack up the front and go from there.

[hammoj28]

Mine was a pain in the ass, had to fiddle about with it for ages. Dreading doing it again.

Been told to park it facing up a slope but I guess jacking as you say would work too. Might help.

[oldroydsr4]

Defo got the rear pipes connected correctly dude?

just to check- which is the right way around?

Back of head to the top heater hose ?

[eko]

Defo got the rear pipes connected correctly dude?

just to check- which is the right way around?

Back of head to the top heater hose ?

No...back of head to bottom heater hose,under inlet pipe to top.

[oldroydsr4]

Nice one tony, I'll double check.

[macas]

I had the same problem,I just bled mine as said before,from the bleed screw at the top of the rad(if it's from the e34 rad)
It took me ages tho to get the air lock out,but I persevered,and it's fine now.
Goodluck

[e30-EVN]

2 days to do mine properly!! Was a right bitch but after my troubles with m20's I was determined to get it right, I don't know how tempremental m50's can be but not willing to take that risk tbh!!

As lee said, rotating top hose through 90degrees to fill the block direct with front end jacked up is the best way, when it pours outa the hose reconnect and then fill slowly from the expansion tank with bleed screw open, tip from myself at this point would be to seal mouth around the expansion tank and blow into it, fill some more and keep doing this until pure coolant comes out of bleed opening. Then you can replace cap and run engine with heaters on hot and full with bleed open to clear last pockets of air.
As said also, good luck with it. Bleed, bleed then bleed again just to be sure

[oldroydsr4]

Just to let your all know.

I've managed to bleed the system ( haven't taken for a spin yet as have no tax) - heater is now toasty and temp is sitting just above a quarter.

Just for future reference-

The technique of jacking the front up high and slowly applying water through the top hose worked a treat, but before I got water coming out the rad elbow, I had to gently blow through the hose (as suggested by dk) and add water as the level went down , This seemed to work very well.

Cheers for all your help.

[e30-EVN]

Good stuff mate

[Dave_M3]

I had abit of trouble trying to bleed my first one too.

Ended up bleeding it the same way I used do with my M42 and it worked a treat... as in just jacking up the front end and kept adding water until whole system was full and all the air was out.