Hello,
Long time lurker. I just picked up a 1975 240D that hadn't been started in 10 years. The guy stored it in his garage after the "fuel pump" went out. It turned out that the fuel pump was the primer pump easy fix and she started right up. the problem is I have no oil pressure.
I changed the oil and both filters. Any thoughts Thanks


1981 300D
1978 300D
1975 240D

Faulty pressure sender... Faulty pump... Chain off the oil pump (if it's the chained variety) Faulty pressure gauge, or broken pressure line to the gauge if it's the that type of gauge

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

I have read that some of the older models have issues with the Oil Pump Pressure Relief Valve or the Valve Spring breaking.

Best to hook up another Oil Pressure Gauge to be sure it is not working.

I missed one. On Engines that have sat a long time I have read of the Oil Pump Screen being Plugged with sludge; but, that was on Gas Engines. But, I assume it could also happen to a Diesel.

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84 300D, 82 Volvo 244Gl Diesel

Can you see oil flying around the camshaft thru the oil fill hole when it's running?

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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

do really,really old dried out shrunken O-rings on the center oil filter shaft affect
oil pressure? [LOTS!]
(BUT.I'll bet it's the Pressure Sender.)

Mercedes Part # 115 997 94 98
It's called a "Seal Ring" in the EPC.
(Two each, per central oil filter shaft,per engine)
Chassis type 123.102
Engine type OM616.912

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'84 300SD sold
124.128

Loosen the fitting where the oil line goes to the block a little. If it sprays oil you have got pressure. Just do not keep this engine running until you get some evidence of oil pressure.

Also if the oil pump is above the oil level and has a little wear it may have to be primed if old and worn the first time. I am not sure if you can prime it by pouring some oil into the filter housing. On a 1975 the oil filter is too low I suspect for this to be applicable. If so it does not apply.

OP has a 75 240D. That would be a 115 chassis. Most likely has the old style oil filter (under the engine, cannister type). If so, the 2 o rings are not used.

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Palangi

2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg



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