300SDL IP does not have fuel pressure
Thread Starter
Newbie
Joined: Jan 2012
Posts: 1
Likes: 0
300SDL
300SDL IP does not have fuel pressure
When I started my 1987 300SDL with 164K miles one morning it ran fine for about a minute and then gradually started to loose power until a minute later the engine stopped running. The fuel filters are fine and the injection pump gets enough fuel but just a few drops seem to come out of the pump with the fuel lines disconnected when the engine is being cranked. Opening the plate on the pump and looking inside shows the fuel rack moving the way I assume it should when the throttle is moved. The overflow valve is working properly. When the car started to loose power the oil pressure gauge was showing zero oil pressure and the temperature gauge was showing overheating. The engine was not even warm at the time. It seems strange that both gauges would do this at the same time.They have always worked fine before. So, with enough fuel going to the pump why is there almost no fuel coming out of it. I took the car to a well known Mercedes mechanic who said he got the engine running but it seized after a few minutes. When I cranked it after getting the car home the engine was not seized.
Does anyone have clue what could be going on?
Does anyone have clue what could be going on?
Senior Member
Joined: Jan 2010
Posts: 301
Likes: 23
1997 E300D
If your oil pressure was really zero, that should be your main concern. It only takes drops of fuel to run an engine at idle.
A lack of oil pressure will stop an engine by slowly binding it up as it heats up from internal friction. This is called seizing, even though it might free up when the pistons cool down. I do not know your engine, but you need to determine if it has oil pressure before you start it again. If you have someone install a mechanical oil pressure gauge, you can normally get oil pressure by cranking with the starter. If it really has seized, and your mechanic should know, It doesn't look good for the engine.
A lack of oil pressure will stop an engine by slowly binding it up as it heats up from internal friction. This is called seizing, even though it might free up when the pistons cool down. I do not know your engine, but you need to determine if it has oil pressure before you start it again. If you have someone install a mechanical oil pressure gauge, you can normally get oil pressure by cranking with the starter. If it really has seized, and your mechanic should know, It doesn't look good for the engine.
MBWorld Fanatic!
Joined: Mar 2008
Posts: 3,714
Likes: 56
From: 1 hours drive north of Sydney Australia
2007 W204 220CDI Classic Sedan
Just to state the obvious , how is your engine oil level, how long since the oil & filter was changed,& how is the coolant level ?.
How does the oil look on the stick. Any sign of water/ diesel. Diesel can dilute the oil.
If all is well it makes me think of an oil p/p failure.
Check the fuel. Make sure diesel was put in & not petrol/gas. It has happened in the past.
Did the mechanic give you any hint to what the problem was.
A second opinion from a diesel or MB mechanic is warranted.
Good luck & let us know how you go.
How does the oil look on the stick. Any sign of water/ diesel. Diesel can dilute the oil.
If all is well it makes me think of an oil p/p failure.
Check the fuel. Make sure diesel was put in & not petrol/gas. It has happened in the past.
Did the mechanic give you any hint to what the problem was.
A second opinion from a diesel or MB mechanic is warranted.
Good luck & let us know how you go.
Junior Member
Joined: Apr 2010
Posts: 47
Likes: 0
From: Albany, NY
2022 S 580; W223
No fuel pressure - 87 SDL
The temp guage/oil press. guage problem sounds co-incidental. My own temp guage at 277kmi+ on an 87 SDL is erratic but I do not worry about it. Non-contact thermometer (using a laser-like beam) corroborates my theory that it is an electro-mechanical failure. No biggy.
Slap the driver side dash (left to right) and the needle should show the acual teperature.........for a while.
I won't comment on engine woes as they have been adequately addressed by others. Based on an earlier experience with a British car a siezed engine will, typically, re-start when cold.
Slap the driver side dash (left to right) and the needle should show the acual teperature.........for a while.
I won't comment on engine woes as they have been adequately addressed by others. Based on an earlier experience with a British car a siezed engine will, typically, re-start when cold.
When I started my 1987 300SDL with 164K miles one morning it ran fine for about a minute and then gradually started to loose power until a minute later the engine stopped running. The fuel filters are fine and the injection pump gets enough fuel but just a few drops seem to come out of the pump with the fuel lines disconnected when the engine is being cranked. Opening the plate on the pump and looking inside shows the fuel rack moving the way I assume it should when the throttle is moved. The overflow valve is working properly. When the car started to loose power the oil pressure gauge was showing zero oil pressure and the temperature gauge was showing overheating. The engine was not even warm at the time. It seems strange that both gauges would do this at the same time.They have always worked fine before. So, with enough fuel going to the pump why is there almost no fuel coming out of it. I took the car to a well known Mercedes mechanic who said he got the engine running but it seized after a few minutes. When I cranked it after getting the car home the engine was not seized.
Does anyone have clue what could be going on?
Does anyone have clue what could be going on?
