Most any loss of vacuum will cause this problem. So for a quick check, just pinch off each vac hose and wait about 5 seconds. If it stops, then you know the problem is on that circuit. If not, keep going till you find the bad circuit. Then with a hand vac pump and some locking tweezers, you search for the leak. Do not forget that behind the switch is a vac switch and it has 2 hoses. They get soft from oil and also come off. Course the first thing you check is if the shutoff vac unit does not have a leak. Then make sure the pump is producing enough vac. It's actually rather easy.
I love it that, even with the bonnet open, from inside the car you can’t hear whether the engine is running or not. So classy.
Most any loss of vacuum will cause this problem. So for a quick check, just pinch off each vac hose and wait about 5 seconds. If it stops, then you know the problem is on that circuit. If not, keep going till you find the bad circuit. Then with a hand vac pump and some locking tweezers, you search for the leak. Do not forget that behind the switch is a vac switch and it has 2 hoses. They get soft from oil and also come off. Course the first thing you check is if the shutoff vac unit does not have a leak. Then make sure the pump is producing enough vac. It's actually rather easy.
Thank you! I have pretty much the exact same car as you. I have a 1985 300SD. Same interior and exterior color.
We have four cars in our household. This one is the oldest. And best.
That's one crusty vacuum line! Good find!
It had roughly the structural rigidity of an overcooked piece of penne pasta. 😂
excellent!
My 83 300sd will do that once in awhile, I just press the brake pedal and shuts it right down.
My '79 300D that I had years ago did this.