Water Circulation

[julielewis]

Hi Shaun
Can you tell me what your " Shaun" bleeding method is.

Julie

[julielewis]

I just installed a new head and head gasket etc because I had a cracked cylinder head etc. I definitely would not let them pull the head because the water flow from the rad to the expansion tank was trickling. Hopefully on Monday I can get more work done on it.

You've just pulled the head because the trickle of water from the rad core to the expansion tank was, er, minimal? I assume you're now going to install a new head gasket and new head bolts, yes?

It sounds to me like the system was poorly bled, or the rad has deposits and/or corrosion at the top, or both.

[E34-520iSE]

I'll PM it to!

Cheers,

Shaun M

[Alan_525i]

Could you post it here so the rest of us could benefit from your knowledge as well? Or is it a trade secret?

[E34-520iSE]

Could you post it here so the rest of us could benefit from your knowledge as well? Or is it a trade secret?

Hi Alan, I used to post my M20 bleeding method on the UK BMW site. I got so fed up of people moaning about it that I have decided to keep it a 'trade secret'. What I will say is that it works 100% of the time on ANY car.

Cheers,

Shaun M

[DaveVoorhis]

Here's how I did it when I had an M20:

1. Open the rad and thermo housing bleed screws.

2. Pull the top hose off the rad. Fill through the hose until it won't take any more. Re-attach the hose.

3. Fill the expansion tank to the brim until it won't take any more.

4. Squish the rad hoses to expel air.

5. Put your mouth over/in (depends on size of mouth) the expansion tank opening and blow hard until coolant comes out the bleeders. Close the bleeders while still blowing.

6. Start the car, immediately rev briefly to 3500 or so rpm (voom! voom!) and shut off the car.

7. Top up the expansion tank. Open bleed screws and repeat the above.

8. Start the car, let it idle and verify it does not overheat.

9. Let the car cool overnight, and top up the expansion tank to the proper level.

[E34-520iSE]

Here's how I did it when I had an M20:

1. Open the rad and thermo housing bleed screws.

2. Pull the top hose off the rad. Fill through the hose until it won't take any more. Re-attach the hose.

3. Fill the expansion tank to the brim until it won't take any more.

4. Squish the rad hoses to expel air.

5. Put your mouth over/in (depends on size of mouth) the expansion tank opening and blow hard until coolant comes out the bleeders. Close the bleeders while still blowing.

6. Start the car, immediately rev briefly to 3500 or so rpm (voom! voom!) and shut off the car.

7. Top up the expansion tank. Open bleed screws and repeat the above.

8. Start the car, let it idle and verify it does not overheat.

9. Let the car cool overnight, and top up the expansion tank to the proper level.

Yep that's the way to do it! When I first posted this method on the UK board a few years back I got people complaining it was dangerous/poisonous/didn't work etc. It worked for Dave Voorhis, and many others too!

Cheers,

Shaun M

[DaveVoorhis]

Well, of course it's dangerous and poisonous, if you drink the coolant. Don't drink the coolant.

[Ferret]

Well, of course it's dangerous and poisonous, if you drink the coolant. Don't drink the coolant.

I'm strongly reminded of that 'Do Not Push' button in that one family guy ep...

Do these engines have the top expansion tank like the 535? If so, I'd make sure that the top bleed line isnt blocked at the expansion tank - they've got a nasty habit of doing that.

[DaveVoorhis]

Do these engines have the top expansion tank like the 535?

No, it's on the side of the rad.