Originally Posted by Brian77

Happy Holidays,

It seems that my car ('85 300SD) hates the cold. The car has recently been cursed by the god Leaky Maximus, in which I have recently fixed a leaking oil pan gasket and leaking power steering pump since the cold weather. Now the car has developed a vacuum leak that prevents it from shutting off other than using the Stop lever in the engine bay. Also, the transmission has developed a rather harsh shifting at the same time. I have spent some time looking at vacuum diagrams and testing various lines with a vacuum pump and think that I have isolated the problem to the main line from the vacuum pump to the brake booster. However, while I ordered the part from the dealer, to be on the safe side, would appreciate a second opinion about whether this could be the problem. I have attached a picture of the vacuum line with comments from when I tested it with the engine running. The car will shut off if I use the hand held vacuum pump.

I tried to rig a temporary solution of running all of the lines through the one outlet on the vacuum line in the picture that seems to have vacuum present, but this fix did nothing to solve the problem of the car not shutting down with the key. BTW, I tried to avoid this problem by having the vacuum shut off valve replaced over the summer.

Thanks,