Vintage Cars: W123 230E 1983

Question
Hi Ron,
My 230E merc, started to billow whitish smoke earlier in the week. She has 270 000 kilometers on the clock and has a fairly comprehensive service history. After checking the engine I noticed the Oil filler cap bits (plastic on the underside of the cap) holding the cap to the cover had both broken off. I have put a new cap on. When I drove it yesterday there was a lot less smoke, but still white smoke from the exhaust. Is this related or is it time for a rebuild?
Thanks

Answer
well whitish smoke can be related to head gasket issues, are you loosing radiator fluid?
Is the underside of the oil cap frothy or have any white/light brown to it?
White smoke from head gasket issue will not smell like oil , but sweeter.  Also slim possibilty that it is ATF fluid drawn into engine compartment by bad vacuum line .

IF you are getting moisture into the internals of the engine, either through a bad oil cap or some other way ( rain ect) white smoke could also be water burning off the oil

Let me know what you find