At which RPM does your oil pressure gauge peg?
 

When the engine is at normal operating temperature, (i.e.: 85C) and idling, my car's oil pressure gauge indicates around 1.5 bars, which is normal.

However the oil gauge only rises but only pegs at 3 Bars when reaching an RPM of 2,200 or so. Is that normal, or should it peg before that.

I am using Mobil Synthetic 0W40. Could this be a contributing factor?

Thanks

Phil

My 94 E300 pegs at 1200 rpm with semi synthetic

Forgot to mention Diesel 145,000 miles

I think mine pegs at just about anything above idle, but by 1000 rpms for sure. Sits just shy of 2 when good and warmed up at idle.
Oh yeah, that's with Delo 400 (15w-40 I think it is)

Both of mine peg by 1000 rpm.

As soon as I touch the accelerator pedal...
 

Literally, as soon as I apply the weight of my big toe on the accelerator pedal, my oil pressure pegs, immedialty!

Change the 2 O-rings that r on the rod ( part of cover )that goes thru the oil filter. That should make a little difference to ur oil pressure (higher). ( If u remover the oil filter cover, u may want to also replace the oil cover O-ring. Does not always reseal well).

mine pegs immediately upon acceleration, but stays between 1 and 2 when idling.

1200 - 1500 RPMs depending on engine/oil temperature. It will stay at 2.5 - 3 Bar when it's cold. 1.4 Bar when idling warm.

Mercedes requires that the warm engine idle oil pressure exceed 0.3 bar and the the oil pressure exceed 3 bar at 3000 rpm. As long as these conditons are met using oil that Mercedes approves for the conditions, oil film strength will be sufficient to keep engine wear to a minimum in a properly functioning engine.

My information sources are the Technical Data Passenger Cars (5/'85 & 12/'88) publications.
Those number will be appropriate with any approved oil that meets the viscosity and temperatuere standards. In truth, when at operating temperatrure, none of my engines ever drop below 1 bar under any conditions and all reach 3 bar by 1500-2000 rpm. That's using Mobil 1 15W50 or Delvac 1 5W40 oil.

Reports I've gotten from owners using Mobil 1 0W40 suggest that the oil pressure numbers are a tad lower and the needle pegs a few hundred rpm higher (but WELL below the 3000 rpm limit).

If the "O" rings (MB # 015-997-94-48) on the oil filter cap stem have gotten VERY hard (they get hard after about 25kmi in my experience) the oil pressure will be lower at idle and rpm will need to be several hundred rpm higher for the needle to peg. If you have hydraulic lifters (OM60x engine) the lifter may be noisier when the "O" rings leak. If the seal within the filter is displaced when installing the filter OR if the filter collapses, oil pressure may never reach 3 bar and the filter will need to be replaced promptly or engine damage is possible.

Marshall

After warm-up, with Rotella T, new filter, and good o-rings, mine idles at 2. and a couple of hairs above. Hits 3 as soon as I hit the accel. pedal.

Idle after partial warm-up:

http://www.lonestar4x4.net/phpBB2/mo...757S.sized.jpg

RPM at idle after partial warm-up:
http://www.lonestar4x4.net/phpBB2/mo...758S.sized.jpg

(see next post]

Continued from above
 

OP fully pegs:

http://www.lonestar4x4.net/phpBB2/mo...759S.sized.jpg

RPM when oil pressure fully pegs:

http://www.lonestar4x4.net/phpBB2/mo...760S.sized.jpg

BTW [thread hi-jack in progress :D :D ), while out tooling around today, I did a couple of ITs (Italian Tune-ups), up to 5,000 rpm sustained for +20 seconds, but it never sooted out. Should I take it up higher or longer?

Mine always pegs cold. Always pegs by 1000rpm when warm.

Oil Pressure Drops
 

The OIL pressure in my 91-300E is at 3 when the car is cold and it runs at 1500 rpm. Once it warms up and it idles at around 700 rpm my oil pressure drops to ZERO.
A mechanical gauge measured ZERO at the Oil sender when the car is ideling.
Just changed the OIL pump (very expensive) New timing belt tensioner and I still have the same problem.:mad:

At accelaration beyond 1000rpm the OIL pressure is 3.
I am worry about the ZERO reading at idle.

Please any one help:confused:
Thank you

Re: Continued from above
 

5,000 rpms for 20+ seconds is sufficient. If it doesn't soot then, it's not going to.