I have Merceds 1987 190D 2.5 automobile. For the last month the engine continues to run for at least a minute after I turn off the ignition. Can I do something about it without taking it to the "Cleaner"?

You have a vacuum leak. The engine is stopped by the application of vacuum to a diaphragm at the rear of the injection pump. Check your vacuum lines to the pump and make sure they're properly in place. From there work away from the pump, checking lines as you go.

I don't know about your particular model, but removing the oil filter at oil change time will result in vac lines knocked loose on the cars I've tinkered with.

Good luck,

You've got a vacuum leak somewhere. Check "search" and you'll find many who have passed this way before you. Round up the usual suspects first (old cracked rubber vac. hose connectors) then proceed from there.


Edit: Larry's quicker!

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

hey thats Mercedes determination for ya... doesnt wanna qui on you.. I find nothin wrong with that.. hehe

btw.. it does sound like a vacuum leak..

take care

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Turk..
00 S500 W220
93 300SE W140
01 C 240 W203
86 SVO Mustang (Turbo Pwr'd.. hehe)

Included in the possible vacuum leaks are the shut-off diaphram itself. Start by pulling the brown vacuum line off the element (shut-off diaphram back of inj pump). Put a separate piece of line to the element start the engine and suck. If the diaphram is good the motor will die. If the diaphram is bad you will get a mouth full of black nasty diesel oil. Its easy to tell which condition exists (bg).

There are so many places that can drop the vacuum so you should start here.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

I've been chasing down a vacuum leak in my 1982 300SD and have a couple of suggestions of a general nature.

1) Never underestimate the brittleness of nearly 20 year old rubber. I have taken to replacing ALL of the rubber junctions and a significant amount of the line itself. I've tested lines out and had them show a leak weeks later.

2) Start at the top. I had multiple leaks, in both climate control and the door locks. But, if you go up to the brake booster (I believe that's the right part), a golf tee can help figure it out. I pulled the line for the climate control off and plugged the line with a tee. The car stopped the next time I drove it (and every other time). It helped in tracking it down.

I still have a few more junctions (and a couple of door lock diaphragms) to replace, but at least the car shuts off for now...

- Ted

I've been chasing down a vacuum leak in my 1982 300SD and have a couple of suggestions of a general nature.

1) Never underestimate the brittleness of nearly 20 year old rubber. I have taken to replacing ALL of the rubber junctions and a significant amount of the line itself. I've tested lines out and had them show a leak weeks later.

2) Start at the top. I had multiple leaks, in both climate control and the door locks. But, if you go up to the brake booster (I believe that's the right part), a golf tee can help figure it out. I pulled the line for the climate control off and plugged the line with a tee. The car stopped the next time I drove it (and every other time). It helped in tracking it down.

I still have a few more junctions (and a couple of door lock diaphragms) to replace, but at least the car shuts off for now...

- Ted

Steve,

I've had an inordinately stressful day. Your explanation of determining the diaphragm condition was priceless. I can't remember the last time I laughed so hard.

For the umpteenth time, thanks for sharing your massive experience here and for throwing in the humor along the way.

Have a great day,

Sounds like the vacuum line alright. try checking the rubber "fork in the road" connectors as those are the frist to go since they are exposed to the heat from the engine in most cases.

The 87 190D has 602 engine. I think the vacuum shutoff module is on top of the FI pump like my 603 engine. Remove the vacuum line to the module and look inside the line. If it is oily, the vacuum module is bad. I saw leaking module that still stopped the engine when vacuum applied. When the module is partially leaking and other part of the vacuum system is in good condition, the driver may not notice any problems.

The bottom line is: if the engine does not stop immediately (a sharp stop with no delay) after key is off, you have a problem. It may be a bad vacuum shutoff module, leaking hoses, bad vacuum pump, or the combination of all of the above. I would start checking for oil inside the vacuum line for the module. Replace the module if necessary. If the engine still does not shut off immediately, you have other vacuum related problem(s). Steve provided detailed steps to check vacuum leakage in the following link:

http://www.peachparts.com/shopforum/showthread.php?threadid=9682&highlight=Vacuum+Leakage


David

Larry,

Real glad you appreciate it. You ought to see some of the humor I have erased. Its real hard sometimes. I never wish to offend and humor can be at others expense if one is not careful.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve , we need a BLOOPERS category!!

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1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
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1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD