79 300sd no oil pressure - Benzworld.org

diesel79 · 03-12-2008, 08:02 PM

Hey all. I'm new to Mercedes and I have a 1979 300sd. I bought it with 195000 miles on it and it has run great until today. It is almost time for an oil change and I drive long distances regularly, so I checked my oil as usual. Saw it was low and added appropriate amount to bring to the proper level. Upon restarting my car I heard a loud engine knocking, posible lifter? I started to drive the car and pressure went from 45 to 0 and I lost most of my power. The car barely made it onto the car trailer. Any ideas? Any and all help is appreciated.

**GermanStar** · 03-12-2008, 08:36 PM

The most likely culprit is an oil pump or oil pump chain failure.

diesel79 · 03-13-2008, 04:55 PM

will that also account for the tapping? or is that a lifter?

79Mercy · 03-13-2008, 04:59 PM

The tapping was the loss of oil pressure.

**GermanStar** · 03-13-2008, 05:26 PM

That was the sound of your valve train sans oil.

diesel79 · 03-25-2008, 03:34 PM

Looks like bad news for my Benz. Oil pump and chain are ok. Bad news is metal shavings in my oil pan. I guess I should start tearing apart the motor. I think it spun a bearing but not entirely sure.

JJSMILHOUS · 03-25-2008, 10:55 PM

Excuding bad oil pressure sensor, sounds like you wiped a main bearing but more likely check the oil filter to make sure the oil pressure bypass is not stuck open. ie. try changing the oil filter before pulling the motor.