"slow" oil pressure?
 

I started my '82 300D for the first time in over a month yesterday. Temps were in the teens and it started right up with a crankcase full of 15w40 conventional oil. That's the good news.

The bad news is that after a 20 mile drive on the interstate I noticed the oil pressure was low. I freaked out and pulled over, and it registered a healthy 1.6 bar at idle just as it always has. Revving the engine slowly, it would peg at about 1200 rpm, but if I revved it quickly, it wouldn't hit 3 bar until 2000 rpm or slightly more.

I've heretofore always run synthetic in winter; is this just the nature of cold,heavy dino oil, or have I got something more serious at work here? I'm really anxious to start driving the car regularly again, but I'd appreciate some reassurance before I do so.

Thanks,
Tom

I wouldn't think that after warming the engine up that the oil would stay cold! If the oil pressure remains low after complete warm up, I would think there is a problem. I would check the oil filter center bolt tube that has two O rings. These rubber O rings get hard and brittle over time if not replaced every so often. Without these O rings, or if they are worn, you will loose oil pressure. :) BB

Good point. Gimme a second to engage my brain...
I will check those. I replaced them about four years ago; I guess it is time again anyway...

Thanks,
Tom

When you say "low" after running on the highway, was this while you were driving it dropped or at idle? I have found here in CT with the cold temps we have been getting, that the oil has a higher "warmed up" pressure. By that I mean, after running on the highway and then coming to a stop, the pressure would be up near 2 Bar. I believe the owner's manuals say that it can go as low as 1 Bar (at idle) if it's hot out and you have been drving high speeds. I don't think you have anything to worry about.