Just a WAG, but do you have oil on the air filter element, or a pool of oil in the air filter housing?
Any modifications to the stock crankcase vapor recovery system?

My best guess is that there is a blockage of the crankcase oil return line.
As a result, rising crankcase pressure will push on the diaphragm of the shutoff valve and cause the car to shut off.
(Just like applying vacuum to the other side of the diaphragm during the normal shutdown with the key).
This will cause loss of power and eventual shut down of the engine (or oil leaks all over the place in severe cases).
This will occur even with the vacuum hose to the shutoff valve being disconnected.

1) Try the external fuel tank with the engine cold and the crankcase breather hose disconnected.
If the engine does shut down when it gets hot, with and external tank connected and the crankcase breather disconnected, then you know it something forward of the primary fuel filter is to blame
(and it's not a blockage of the crankcase oil return line).

2) If the engine does not shut down when hot, with the external tank connected and the crankcase breather disconnected,
you know it could be something aft of the primary fuel filter or that there is a blockage of the crankcase oil return line.

3) If the engine still runs when hot, reconnect the crankcase breather hose to the valvecover.
If the engine now shuts down, you know there is a problem with the crankcase oil return.
If the engine now doesn't shut down, you know the case is aft of the primary fuel filter.

If excessive crankcase pressure is causing the engine to shut off: another way to test would be...attach a pressure gauge (MityVac set on pressure) to the shutoff valve when the engine is cold,
and check see if it the pressure increases as the car shuts off when hot.
I suspect the amount of pressure to activate the shutoff valve (backwards of it's intended fashion) would register on the MityVac gauge.

This was the only thing I could think of that would completely explain your symptoms, including the inability to restart the car.
If it's not a blocked oil recovery line at the root cause of your symptoms, then I'm stumped for now.

__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

If the engine will not turn over well when hot and restart. Some wd 40 sprayed down the intake throat with the air breather cover off might be worth trying.


There is a chance if it will not light off this way the engine is partially bound up. You mentioned a squeeling noise at one point in your descriptions that was not identified.


Part of your description looks like it may be binding up a little more as it warms up. With the glow plugs out the engine should turn fairly freely.


This post is just an item that cannot totally be overlooked unfortunately. Not a certainty it is the problem.


Hot it would not crank well but more like a very weak battery. Yet cold the next morning it would crank normally. This is not normal. Also this clang noise you hear might be related to a bearing failure or something else mechanical.


As an example if you ever get a clang on engine shutdown. More times than not you have a broken crank. These engines fortunately have a robust crankshaft and seldom break. At the same time bearing issues are known.

Have you put a socket on the crank bolt and tried to turn it over manually when it acts like the battery is dead to see if the engine is getting tight? Or at least tried to turn it with a crescent wrench on the PS pulley bolt?

__________________
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

Just tried this. It is turning the same way it always does.

I changed the inline fuel filter yesterday even though it didn't look bad. I just took a look at the new inline fuel filter and noticed some black and orange particles floating around. I pulled it off and cut it open and it had a little ball of sludge in the screened area about the size of a small pea.

I'd like to think this is the cause of my issues, but the filter was brand new yesterday and it did not run any different when it was brand new.

Sounds an awful lot like a seizing bearing + knocking rod to me. A bit of deja-vu from the first thread you posted with the squealing and finding the rag shredded in the valve train

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

I'm not sure that's a rod knock. It comes and goes. I don't see how a rod knock could come and go. But something's seriously off with that engine.

__________________
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

Timing chain slap?

__________________
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

Maybe the timing chain has jumped some teeth?

__________________
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

I had the valve cover off about a week ago to check this and the timing marks on the cam and on the crank balancer aligned perfectly at top dead center.

I see this statement a lot. In reality, it is just about impossible for a double row timing chain to jump a tooth. Next time you adjust the valves, look at the timing chain and how it is mated to the sprocket and you will come to the conclusion it is nearly impossible to jump a tooth.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

It sounds too tinny for a rod knock.

__________________
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

Has something happened in the meantime to produce the current symptoms?

__________________
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

Up until yesterday, it would at least idle while cold and drive (very slowly) and was only making that intermittent squeaking noise you heard on the video. Once it got hot, it would die. Then yesterday I tried to get it to start and was getting what you saw in the video. It would only idle if I stood on the pedal and even then it was idling very roughly and making all those terrible noises.

I can't think of what else would be making that sound apart from the timing chain.

__________________
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