Oil pressure slow to build after oil changes

[mabbonizio]

Hi Folks,

wondering if this is normal or not.

I usually drive my 82 240D approx 20 miles before changing the oil. I don't do this purposely but because thats how far it is to get to my parents house where I can change it. Thus the oil is nice and hot when its drained.

Sequence is that I pull the drain plug and drain the pan. While thats happening I remove the filter, clean the filter canister lid - install new o-rings and re-install the filter and canister lid. I do not fill the filter with oil.

Then I re-install the drain plug and fill it up with about 6.5 quarts. check for leaks and check the dipstick and start it.

I've noticed on the last two oil changes that when i start the car it it does not build oil pressure, the engine will actually start to clatter. Then I shut it off. Restart it - engine starts to clatter, and it will build half a bar of oil pressure slowly, then rise to 3.

This all happens in a matter of 10-20 seconds but seems like forever when its happening. Am I doing something wrong? this is how I have always changed oil.

Should I be pre-filling the filter canister with a quart of oil or something?


For reference when the car has sat for any period of time (even over night) it fires up and immediately builds 3 bar oil pressure. Hot oil pressure is 1.75 bar and coming off the high way on a summer day when I've been cruising at 65-70mph it will be a hair above 1 bar, then rise pretty immediately as the oil cools a bit to 1.5 bar.

Lastly, why do I always get two large o rings in the filter kit? one is thick and one is usually thinner.. I just use the thicker on under the canister lid and pitch the other one?

thanks!