I'm driving up a hill. Silly me, I tried to keep up with a Neon. Suddenly, I hear a bang, and pulling off the road am enveloped in a cloud of white smoke. It shuts down slowly when I switch the key off. I try to restart after a few minutes, and it starts but runs ragged.

So I walk two miles to a tow company, and bring it home on a stretcher
(85 190D 4 cyl). Here in the yard it runs smoothly, but with some oil burning.

At no time did it get hot, nor lose oil pressure. The coolant is clear, and the oil seems ok too. I had a lot of blowby before, and I still do.

Did I blow a head gasket? Do they actually "blow"? Why are the fluids not contaminated? I think I dodged a big old bullet!

A bang you say? maybe the timing chain jumped a tooth and a valve made contact with a piston (worse case scenario)

or you hit something on the road and its all coincidence?

Check your vacuum pump.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Kerry: Interesting idea. I went out and started the car. Brakes ok. Tried the door locks--not ok at all. The aux pump in the rear wouldnt shut off, engine running, with engine off, the locks were slow to drop.

Better yet, unlocking was hard, and I could hear a hissing under the passenger side carpet. So what was all the white smoke?

mostlikely its the vaccume pump. the roller bearings went out in it causing the injectionpump to skip a tooth. now its injecting too late and pouring diesel out the tailpipe.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

That makes two in favor of vacuum pump. There could be some vacuum issues. I can see a surge of fuel causing a bang. But how to account for its running ok after the fact if the injector pump is off a tooth? .

I would test the vacuum today but I have to go away for a few weeks. This working thing--I should never have started it...

you got lucky with the jumped tooth, it was probably on the beginning of the compression stroke or somewhere in the exhaust stroke..

if it was towards the end of the compression stroke the cylinder and valves would make contact, not good.. but it appears you did get lucky

This is a wrap up of this thread. Maybe its helpful to someone, somewhere..

A local diesel mechanic looked at my running engine, and after feeling the exhaust ports, declared that my #1 cylinder was dead. From this forum I find that these 601 engines are noted for head gasket failure on #1 cylinder, so I printed out the FSM and studied my Haynes, and decided to change the head gasket, my first on any kind of car.

It took a long time, but was fairly easy: I painted a spot on the cam sprocket and gear, set it to TDC, and tore into it. On this model you drop the timing chain down into the block, so I was worried about losing the injector pump timing.

After I had it apart, I got my friend over for an autopsy. the gasket showed discoloration on both #1 and #4, so that was the problem. Having an experienced person around to tell you what you're looking at is a vital part of doing this kind of thing.

I discovered a cracked timing chain guide rail and replaced it. Everything else seemed more or less right for a car of this age so I left things pretty much alone. I had to order a socket for the head bolts, and although it was advertised for om601 engines, it didnt fit until I drove the shaft out of the socket and used it was an extention. You need a slide hammer for the timing chain guide rail pins, and there's no escaping the removal of the radiator, and in my case the a/c condenser, so dont fight it.


But tonight I refilled the radiator (discovering a thin film of oil on the antifreeze after all) and the crankcase, cranked it over for a while, and lo and behold it started.

Thanks to this forum, because I never would have tried this else... remarkable how well it ran on only three cylinders.

Congrats on the successful repair. Thanks for the follow up.

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1959 Gravely LI, 1963 Gravely L8, 1973 Gravely C12
1982 380SL
1978 450 SEL 6.9 euro restoration at 63% and climbing
1987 300 D
2005 CDI European Delivery
2006 CDI Handed down to daughter
2007 GL CDI. Wifes