Quit trying so hard to be right... and contradicting yourself in the process!
Need I explain how and where?
There are no contradictions in my posts.
Did you ask if I had to continually add more coolant? Did you ask to what extent I was overheating, or
if I had tried to bleed the system before my mechanic friend did? You assumed that I left the car at a shop
and may have no idea what he did.
Further, you do not understand as much as you think you do of our cooling systems. Do you know the
difference between a serial and parallel type cooling system, and which of those the M50 design is?
Only a capital fool would not bleed the radiator before calling in a mechanic and you clearly are not a capital fool so i didn't bother with that question. And I know enough about our cooling systems my friend, to....
Do some reading on "air pockets/hot spots" in automotive cooling systems, then come back and tell me
that they cannot cause a coolant loss or overheating.
....tell you that hot spots in the engine will not cause you to loss coolant, as coolant vapour does not osmosize or beam itself through the metal and plastic of an engine and a radiator. It will remain trapped in the system and eventually condense back into coolant once the car cools down after shutoff.
Vapourised coolant will of course get out of the car through a ruptured hg, cracked head, or other ruptures in the rad and rad hose circuit.
The white smoke and froth under the oil cap was simply condensation from hardly being driven,
and this occurred during the winter. Can you grasp that? Research this before you profess to know all,
unless you are simply making suggestions, clearly you've read that many overheating problems on
this car are due to faulty water pumps or thermostats, and are dwelling on that, suggesting that one
or the other MUST have been causing my problem. OBVIOUSLY neither was the cause.
As mentioned, it was misleading to include mere condensation in your original writeup and suggest that this had something to do with coolant loss.
Now! If you have any new thoughts on what actually solved my problem I'm open for entertainment!
Oh! FYI, my car never went to a shop, was never out of my sight, and I was present when my buddy came
to my house to bleed the system.
I repeat; no further issues!
I posted my experience as food for thought, not in disagreement with your opinions or suggestions on the
OP's situation. Why are you trying to help me with a non issue?
And I responded in good faith. As mentioned, 1.5 expansion tanks worth of air made it through my engine slowly over the course of 3 weeks without causing any overheating in the least. If you know how much 1.5 expansion tanks of air are worth...that's something like 3 litres or so. Our cooling system's capacity is 11 litres. Conclusion ? Reports of overheats due to air pockets are greatly greatly exaggerated and likely to be false positives, concealing other issues. I suspect your problem got solved coincidentally (not unheard of in old components), which means its still lurking, and most E34 overheats are caused by buggy thermostats and wps so that's where I'd attack first, just in case. I could be wrong of course but I highly doubt that. And my mechanics who do BMWs all day long confirm that trapped air pockets is not a known problem for our E34 engines, both of them, unlike what your mechanic seems to think.
Its your car and you are welcome to carry the risk. Pm me if you feel you need further clarification.