help!!! Diesel in distress - PeachParts Mercedes-Benz Forum

grimgaunt · #1 05-30-2003, 08:55 AM

This is a diesel that I just bought,. Owner said he knows nothing about the beast, except that it was 'loud' , when I got it it started right up and ran fine for a bit then (2-3 miles) died !!! Never had a diesel die like that, so I had it towed and in the morning cranked it and it started up first glow. The loudness by the way turned out to be 3 broken air cleaner mounts.
Drove it to a local mechanics to be serviced (oil, air and fuel filters and tranny filter and flush) it died on the way there.

Pushed it into the bay and changed both fuel filters and air filter used their battery charger and cranked right up, then died

Hasnt started since.

Had it towed to a diesel mechanic (Hans in Hampstead, NH) where its been sitting for 10 days until he could get to it , I am doing this long distance from Denver at this point because I had to fly back (I bought the car over EBAY, car is in Boston area)
This morning he calls and says - ' car cannot be turned over by hand, but starter does turn it over, seeems to be a huge drain on battery (new by the way)'
He is going to tow start it later this morning..

P.E.Haiges · #2 05-30-2003, 09:23 AM

Grimgaunt,

Does the starter crank the engine after it stops running? Or is the engine siezed and won't crank until it cools?

How was the oil pressure when it was running?

P E H

Fredmburgess · #3 05-30-2003, 09:24 AM

Grimgaunt, what model is it? My experience is limited to the '84 300D that I've got now, but it sounds like fuel starvation or air in the fuel system. When the car quit, did it shut off abruptly or just start stumbling more and more until it just couldn't pull itself along (air). Obvious question, but was the air purged from the system with the hand pump after the filter change? Tank's full of diesel, right? Ok, really obvious stuff, but not much to work with. The diesel guy's probably already got it running, although kind of puzzled about the need to pull start it...

Fred

grimgaunt · #4 05-30-2003, 09:41 AM

I purged it, but the primer pump is leaking horribly, that could have let more air in the system perhaps ??
Yes the starter cranks fine if a bit weakly,

Wasuchi · #5 05-30-2003, 09:56 AM

Don't forget that there is a filter/strainer in the tank also.

kerry · #6 05-30-2003, 10:25 AM

There may be two problems: a fuel problem and a starter problem. One way to test the fuel system is disconnect the tank and run it on another supply, as is done when running purge thru the system. That will tell you if there is a problem with the lines from the tank or the tank itself. It won't help if the problem is air entering from a bad hand pump.
How did the mechanic try to turn the engine over by hand? Not being capable of being turned over by hand seems like an odd and inexplicable symptom to me.

grimgaunt · #7 05-30-2003, 10:57 AM

pressure was good, it was at almost 2 when it was idling and pegged when driving.
I dont know why he would try to turn it over by hand unless he was timing the injection pump or something !!!!

Heres what I have to go on re: compression
after I had it towed when it died, it started up first crank smooth next morning when I glowed it, it was in the upper 30 's when I did this, so basic compression would seem to be OK.

edge · #8 05-30-2003, 11:39 AM

Wow, what a drag for an Ebay buy. Try to get your money back, was it a dealer?

grimgaunt · #9 05-30-2003, 11:45 AM

no, an individual, I bought it knowing
'it ran loud' - could have been anything from injectors to broken pre-chamber

I think its been neglected for a long time.

dabenz · #10 05-30-2003, 08:06 PM

Sounds to me like an exhaust restriction, especially if the mechanic can't turn it over by hand. Something's holding up the pressure and killing the engine. Perhaps the muffler or resonator has something loose in it. But first I'd check that the crankcase breathing system is clear, then the air cleaner.

JimSmith · #11 05-30-2003, 09:18 PM

grimgaunt,

What model/year is it? How many miles?

I would agree with some of the other assessments above that suggest you either have air leaking in or you have a clogged vent on the fuel tank. Either one will lead to problems and the latter leads to an abrupt loss of power and very peculiar fuel gage activity. Getting the fuel tank filler port cap off can be a real chore if the vent seal is clogged and the engine has shut down because the tank pressure is below the suction pressure requirement of the fuel pump.

Air leaking when the car is running would seem to me to have to be a huge air leak to cause a problem unless the filters were clogged. If you just changed the filters you do need to purge all the air out of the system or the car will not be able to get fuel out of the injectors and into the prechambers to fire. Lots of words for the engine will not start.

When the machinery exhibits similar, aberrant behaviour under various circumstances, it is often concluded that all the instances of the aberrant behaviour are due to one possible flaw or system failure. This may not be too clear, but, in your case your original problem was the car would not stay running but it apparently would restart ok, maybe not immediately but shortly thereafter. Then you did some work on the fuel system and it will not start. The not running and being hard to start after shutting down on its own while running may not be related to not starting after replacing the filters, or it may have a peripheral relationship.

So, solving the present problem of not starting at all may not be of much value to the "won't keep running" problem. The "won't start after changing fuel filters" problem is pretty common and can be due to a slew of single or combined conditions. The most common is getting air that was introduced to the high pressure fuel system during the filter change, back out. This is further complicated by a poorly running primer pump. But it can also be that the battery, starter and glow plugs are all, or in pairs or alone at the edge of acceptable operation and a little air just puts the system over the edge. In any case solving this problem is likely pretty straightforward.

The "won't keep running" problem is less common. The fact that it runs again afterwards is encouraging and leads to possible scenarios like the clogged tank vent, or some other intermittent type of problem with fuel delivery. To help from afar we need more data.

What happens when you open the tank filler cap? Does air whoosh in? Does the car run afterwards? How does it shut down? Abruptly or does it just fade? Does it get rough running and shake before it dies or does it stop like you turned the key off?

Good luck and I hope we can help. Jim

grimgaunt · #12 05-30-2003, 10:51 PM

Jim
the car has 240 kmi on the engine
The fact that it restarted even in the cold , the morning after the initial 'dying' incident tells me that basic compression was ok.
The air in the system could be a major factor, any help appreciated.
The fact that the 'german' mechanic does not take suggestions easily (or not at all) and I am 2000 mi away does not help.

Anyone want a good SD for cheap

grimgaunt · #13 05-30-2003, 10:54 PM

one more thing. when I replaced filters, I filled the spin on with diesel purge and started it, ran fine for 1 min, then the idle sort of 'oscillated' and then died. NEVER started since !!!

JimSmith · #14 05-30-2003, 11:09 PM

grimgaunt,

Was that LubroMoly Diesel purge? I just did the same thing on my daughter's 1982 240D today, and it worked fine, so I don't think that is really the essence of the problem. I would be more inclined to suspect the air leak or the tank vent clog. Keep us posted and good luck, Jim

invisik · #15 05-06-2004, 06:36 PM

This was last year, I realize, but does anyone know what the problem was on his car? Sounds like it could have been anything!

-m