My 1982 Mercedes Benz takes 2-3 minutes after taking the key out to turn off. What could be the problem?

Answer 1

First of all, Diesels don't experience "dieseling", as odd as that may sound. When a Diesel keeps running, it's because the fuel cutoff on the injector pump isn't working correctly. The most likely problem is a vacuum leak. Unfortunately, a Mercedes vacuum leak anywhere in the car can cause this symptom. So you will need a vacuum gauge and you will need to inspect the vacuum system branch by branch.

On a gasoline car, you can get "dieseling", which is a condition where hot spots in the cylinder ignite fuel. It's characteristic is a "chuff chuff" sound before the engine gradually dies.Chage the plugs and check the timing if this is the problem. If the engine runs smoothly and finally stops normally, a possible cause is a sticky fan relay... a freewheeling electric fan can generate enough current to keep the car running for a little while.

Answer 2

This problem is known as "dieseling". Regardless if the car is diesel or gasoline. This happens when the combustion chambers in the engine are so gunked up with carbon deposits that they increase the compression ratio, glow red from the heat of the normal combustion cycles and retain that heat once the ignition is shut off. These deposits are hot enough to ignite the fuel without spark. Modern fuel injection systems won't allow fuel in once the key is out, but that may not be the case in 1982. I would be inclined to say that if you do have a gasonline powered MB, that it is carbuerated (Most US cars were back then, but I'm no expert on Euro's of that vintage)...and the carbuerator will allow fuel in the motor if it is still getting a vacuum from a spinning motor.

Now, if your MB is fuel injected...the problem is compounded. Like I said before, a properly working injector should not allow fuel to spray with the ignition off. So, not only do you have a carboned-up motor...but maybe a leaky injector as well.

Either way, do this first...Get a bottle of good quality "complete" fuel system clear, not the cheap "carbuerator" cleaner. A product called "Seafoam" is the one of the best at this kind of deep engine cleaning. Its a 3 step process. 1/3 of the bottle in the fuel tank, 1/3 in the oil, and 1/3 directly in the intake manifold (usually suctioned in through the brake booster vacuum line with the engine running) Follow the directions closely. The engine will stall out on the last step. That ok, let is set for a bit and start it up, and drive off (somewhat hard). You'll get to see a wonderfull smoke show out the rear of the car. This will clean out all the carbon in the motor. If you still have the problem, get your fuel system inspected by a mechanic.

Answer 3

Get the timing checked

Answer 4

is it a deisel, or what. it is probably a vaccum leak.