Hi Louis, I have just read that thread attentively, but here the issue seems to be quite a different one. My engine starts very readily when cold (it takes about 1 second for the starter to have it running...) and I don't have the blow-by noise issues or smoke and pressure coming out of the oil filler cap described in that thread.
The problem for me is the engine OIL ITSELF coming out of the breather hose junctures - and not the oil cap! When I replaced the air filter yesterday, I removed the whole thing (air filter housing) and inspected underneath it, the lower breather hose juncture (where I had placed a screw clamp also in 2005) and the manifold opening...
There was also oil (filthy, greasy) there too and all around it (as well as a bit of it on the bottom part of the old air filter where it sits against its housing), which I thoroughly cleaned out before reassembling...

Did I miss something in that thread, or what it describes is an altogether different issue?

Thanks,
Rino

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1979 240D, W123, 105K miles, stick, white w/ tan interior.