GIZMOID

W124 300D Take out the ignition key and the engine runs on as if nothings happend.

What could cause this?

If anyone has any ideas it would be much appreciated.

pointman

i remember my grandma had a 300d turbo, did the same exact thing. dealer replaced ignition cylinder....all good after that.

mb-mopar nut

there is a fuel cutoff solenoid that shut the motor down. The car can run without electrical power so I assume is takes a power source to shut the fuel off. There is usually a manual level to cut fuel as well. Dig around.

pointman

the manual lever is located under the hood, to the right of the motor... it has a red marking on it...but that is only a temporary solution.

Steve Clark

vacuum leak.

sph17

My W123 would do this whenever there was a vacuum leak. The vacuum is what would activate the engine shut off, as there is no "ignition" to turn off.

With the W-123 the most frequent place for a vacuum leak is by the firewall on the driver's side. This is where there is a valve with a nuber of vacuum hoses comming into it, with one going out, into the fire wall. Thsi is also right near the oil filter housing, and changing the oil filter would often dis-lodge the vacuum hoses. I don't know if your engine arrangement is similar.

pointman

i guess he doesnt care... alot of responses but no answer from him.

Sam 325i

My 124Diesel did the same thing.

You blew the vacuum pump. And possibly the a belt or two, it cost me aruond $500 for all the parts I needed, and about 4 hours of my own hard damn labor.

GIZMOID

thanks a lot guys sorry i diden't get back to this thread had major problems with computer as well as the vacum pipe on the bulkhead all sorted now much appreciated i'm obviousley not destin to save this car from the scrap heap.