Oil filter spring?
 

Guys,
What is the point of the spring on the oil filter?

-Steve

If you have so much crap in your oil that the filter plugs-up and can't flow through the media the oil pressure will override the spring tension (differential pressure, PSID). This will allow the oil to by-pass the filter media and continue to provide the engine with oil for lubrication.

It will be dirty oil, but if your filter is so contaminated causing a by-pass you have more problems than lubricating with dirty oil.

P.S. To better explain; in a perfect world with oil flowing through a filter and no restriction, the pressure is equal on both sides of the filter media (paper). When the filter becomes clogged these's a pressure differential and that differential pressure is what will cause the spring to compress and open, allowing oil to by-pass. Now the argument about by-passing during high RPM's, if the flow is so great the media won't flow the oil OR during cold start-up when the oil is thicker I can see it.

I don't know specifically for this car, but it's not just if the filter is dirty, it also helps keep from oil starvation in times of high RPM oiling needs by bypassing even a clean filter.

Thanks for the explanation! One more question, does the spring go inside the filter or on top of the filter - I don't remember how it was positioned last time I did it myself.

thanks guys,

-Steve

I can't help you there. I've never noticed a spring or bypass mechanism (maybe not paying attention?) let alone had it come off when changing my oil on the Boxster.

I either did not notice either or I just do not remember after two years. Dealer does it on even years. Memory not what it once was. :)

I just recently ordered the canister filter adapter from Jake Raby's Flat Six Innovations. And a magnetic drain plug. For this year's home change.