low oil pressure
 

I HAVE A 83 300D TURBO. 190K WITH .2 BARS WHEN HOT! I HAVE CHANGED OIL PUMP, RODS AND MAINS. NO CHANGE. USES MINIMAL OIL.... 1 QUART OVER 3K. ANY IDEAS... PLEASE HELP!

what weight oil do you use? is it syntehtic? have you checked the actual oil pressure guage? 1 quart over 3k miles is not negligible for a benz.
m

Yes, you need a second opinion.

That is, a second oil pressure gauge to confirm you really do have low oil pressure. I always mistrust the instrument first. That's usually the cheapest to fix.

Good luck,

Ken300D

OIL PRESSURE
 

I DID CHECK THE OIL PRESSURE GAUGE, AGAINST ANOTHER GAUGE, NO CHANGE. I HAVE TRIED 20 W 5O SYNTHETIC TO 30 WT ROTELLA T. STILL NO CHANGE. I DID TALK TO A MERCEDES MECHANIC, HE IS CONFUSED, AND HE DID SAY IT WAS NORMAL FOR A DIESEL TO USE 1/2 QUART TO 1 QUART OF OIL PER 3K.

Maybe there's a bad relief valve somewhere. Hopefully it's in the oil filter stand, and not somewhere inside the timing chain cover or oil pump.

Sixto
91 300SE
87 300SDL
83 300SD

LOW OIL PRESSURE
 

WELL THATS WHAT I WAS THINKN, JUST MAYBE A RELIEF VALVE. THERE IS A OIL THERMOSTAT THAT IS SUPPOSED TO ACTIVATE WHEN THE OIL IS TOO HOT. BUT THAT NEVER SEEMED TO OPEN, SO WE JUST TOOK IT OUT THINKING THAT THE OIL WAS NOT CIRCULATING, THEREFORE OVERHEATING THE OIL AND THUS THE OIL PRESSURE DROPS, BUT STILL NO CHANGE. IS THERE A VALVE INSIDE THE OIL FILTER HOUSING THAT COULD BE STUCK OPEN???

changing the guage is only part of the issue. did you switch out the sending unit. That is what actually tells the gauge the pressure with an electric signal. Unless you have one of the older ones where the tube actually goes into the guage in wich case ignore my ramblings. I still maintain that a quart of oil every 3k is not normal. My 220d never used oil over a 5000 mile interval. Nor did my folk's 300td's.
m

AFAIK an 83 300D doesn't have a sending unit. There's an oil line that runs to the mechanical gauge.

Sixto
91 300SE
87 300SDL
83 300SD