E30 Zone

Hi there,

I recently changed my cambelt, waterpump and thermostat. I bled the system and everything seemed ok.

Then it started overheating again in traffic but settling down when moving, so i narrowed that down to the fan - Ive now changed the fan.

Thing is i have gone to re-bleed the system but i cannot get heat out of the blowers. The heater control valve then started leaking, so ive replaced that as well.

When it gets up to temperature, there is no heat out of the heaters, only steam seems to come out of the bleeder, then it splutters out water (sometimes spraying it out!) the bottom radiator hose is cold and it sounds like the water is bubbling and boiling in the expansion tank!

Im really at a loss as to what to do now, do i empty the coolant again from the radiator and start again? Ive tried jacking the car up at the front but no joy. No mayo on the oil cap or dipstick, coolant in expansiomn tank is clean.

Anyone? I just want to drive my weekend car!

Cheers

Heater circuit airlocks are easy to clear! Fill the coolant bottle right up, take off the top heater hose on the bulkhead, and push it back on when coolant runs from both sides.
If this is a M20B25, running it with this airlock is an extremely effective way of cracking the head!

Its a 320i. Do you mean the two pipes that go into the grommit and into the engine bay - Where the heater control valve pipe comes out? So take it off then wait until coolant comes from the pipe and the hose>?

Any idea why the lower hose for the rad is cold?

yeah thats how ya do it m8 had the same prob when i got my rad fixed and changed my heater matrix

the lower hose is cold cuz of the air lock should heat up as the air leaves the system

Amazing, all fixed now, temp is always below centre! Thanks for the help! Problem cured.