But I don't beleive the 240D would have a vacuum line from the brake booster to the intake. A leaking master cylinder, leaking into the booster, could put brake fluid into the vacuum system. How's the brake fluid level?

Deezel, Thanks for getting me thinking outside the box. But probably no value on this one.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

The car is a manual 4 speed ,but maybe here's another clue after an oil change (religiously 3000 miles) the car won't burn a bit for say 7 or 8 hundred miles (Though it still bellows white smoke at idle and let off ) then it might use a quart very quickly ,maybe one hundred miles then go back to not using much. I even let an old friend that has operated heavy equipment all his life (he's 81 ) talk me into trying a quart of powerpunch on one oil change (I really don't belive in oil additive) and that made no change, it dose show some blow by compared to my SD that use's no oil at all...
William Rogers.....

William,

Wow, I just realized there are a lot of William's on this forum!

I have a 76 240D with automatic tranny. I had the same problem about a year ago. Large amounts of white smoke billowing out of the rear whenever I let off the accelerator, to take an off-ramp or coasting down a steep hill. I then started seeing more and more smoke when cruising down the interstate at 70 or more. After a little longer, the smoke was visible anytime I was not accelerating. Power was down and fuel economy was going out the window.

I believe Mike had your answer, because after I did a valve adjustment and replaced the valve stem seals, MY smoke-screen disappeared! Hope this will solve your problem as well.