I changed the oil on my daughter's 2003 Cooper R50 yesterday. I did a couple of upgrades/mods at the same time:

First, I installed a Fumoto oil drain valve after having one h??? of a time getting the drain plug out last time. Next, I replaced the oil filter cover with the "new" version that was spec'd for builds after 7/2004. Finally, I switched this fill from Mobil1 0w-40 (Euro) to Castrol Syntec 0w-40 (Euro). I used a Mann filter - HU 816/2 X - same as last change.

Everything went as expected - until I drove about 20 miles. Then the red oil-pressure-low indicator illuminated on the dash when I was stopped at a light. If I rev'ed the engine, the light would go off just over 1000 RPM. When the engine settled back to idle speed, the light would come on again. This only occurred when the engine was fully warmed up. After the engine would cool, no problem - until up to operating temps again.

So I read every similar thread I could find. I started chasing ghosts: I looked for the displaced spring on the oil pressure switch - it was fine; I checked for leaks - none; I cleaned and re-tightened the oil-fill cover - check. Removed, cleaned, replaced oil-filter cover - problem continues. I even checked to see if there was a different part number for the filter itself, depending on which filter-cover was in use - they're the same.

I then decided I'd go backwards with what was new, starting with the new oil filter cover.
Voila! Changing from the new cover, back to the old cover with integral plastic cage and spring, and the light now stays off at idle. So this gets me to thinking about differences between the old and new, and there seem to only be 2: first, the old cover with an integral spring would likely seat the filter more firmly and consistently against the inside of the oil-filter housing, possibly making a better seal; second, the integral cage - which should be redundant because Mann filters have their own internal support cage.

In the first case, maybe oil (some/all) can bypass the filter, thereby reducing resistance, which would show up as lower pressure. In the second case, the redundant cage might actually be restricting flow when the old cover is used, but allowing more free-flow through the filter when the new cover is used (which I presume would be a good thing), which might also be read as lower pressure by the ECU.

So for now, and until the next change, I'll keep the old cover in place. BUT, I'm very curious what you all think. Short of doing a pressure test with old and new covers, and comparing results, I'm at a loss - and I don't want to risk engine damage using the new one.

 

I just did the exact same thing on Thursday with the wife's '03 R50 (I have an '02, and both have the cage/spring assembly in the canister. I had been using the Mahle filters previously and while they are rigid inside I don't believe that they have the type of cage thing that the Mann filters have. I was worried that the cage in the filter wouldn't fit over the existing cage but it does, and very nicely. I would not be worried about the double caging, but I would be worried about the low oil pressure light you saw. I believe that the pressure sensor is elsewhere in the engine so if your double caging were actually reducing the flow the light would come on then as well.

Curious- why did you get the new canister- to avoid having the low oil pressure problem later on if the spring/cage got tossed by some quickie lube place?

Val

 

It was nagging at me that the double-cage might restrict flow. Plus I had a miserable time getting the old filter off the cage the last time I changed the oil, as well as this time when I resorted to a 3-jaw puller to get enough leverage to get it to separate. I figured that, it was a better solution all-around to go with the newer style cover. Guessed wrong on that one ...