PSA ::: Oil Pump By-pass " upgrade"

I keep hearing recommendations on the "InterWeb" from tons of people telling others to "upgrade" the Oil Pump By-pass Valve and Spring to the "new version" .....This is NOT AN UPGRADE ....Let me explain .... The Spring is the same as always part # 996-107-127-53 ..costs about $10 The Piston is the same as always save the small chamfer at the top part # 997-107-125-01 .. cost about $15 The reason for the small chamfer at the top is due to the 2005 987 Boxster M97/20 engines has a slightly different oil pump housing casting that when started cold would produce a high pitch squealing sound for a minute or two then stop ( high viscosity oil forced through a sparpend channel)....I was involved with one of these early 987 M97/20 Squealing Engines that originally had the " 996 piston" that I took to the bench grinder and cut the 45* chamfer on top to break the sharp edge that was causing the noise when combined with that housing .....All new production by-pass pistons got the chamfer ( and a new part # ) as it has no effect on the older housings and can be used in ALL housings... The new Piston with the new part # will have NO Effect on oil pressure what so ever.. The Spring that is the same as always can have an effect at high pressures if it is weaker than new...or can have an effect even at idle if it is broken .....Broken Springs are quite rare and weakened springs can only effect the maximum pressures ... With so many people regurgitating the fallacy that this is an "upgrade" and at only a $25 cost, it is unlikely to change, but YOU now KNOW the TRUTH ......

Did your work get published in a TSB? And how long does a new spring typically last? Probably like 5 years?

Quotes source post: 20135840

Yes there was a TSB published in early 2005...for clarity it was not "my work", I was just involved with the Porsche Engineers to solve this problem ........because I had one of the first effected cars/Customer Complaints ...we had to work together to try a few things first before hitting on the root cause... All my cars have the original Pistons and Springs in them..... Sally is 26 years old and 194K miles and still has over 115 PSI oll pressure on cold start ....( measured with a True Pressure gauge at the oil filter)...so I think the Spring has not weakened very much It only takes 10-15 min to pop out the Piston and Spring and have a look to see if the Spring is broken...IF the Spring is not broken and Piston is not jammed,, there is really no reason to the replace them....but if spending $25 to replace them gives you the warm fuzzys, then who am I to say no ??

Quotes source post: 20135772

Going on my list of things people replace on the 996 that functions perfectly.

Thank you, that is very good to know.

Is this the 997 upgrade you are referring to? I was having low OP at idle after a hot run up the mountain but not really any other time. I did this mod and replaced my oil with Driven DT 40. After I did that I no longer get the LP warning Not sure which changed but something def did. The old one appeared fine, but if I recall I thought the new spring seemed stiffer... but it's been a year ago. based on LN engineering recommendations.

Quotes source post: 20135881

That�s really cool! Let me guess: this wasn�t the only time you had to help the engineers out? You probably have helped out with many other TSBs, lol.

Quotes source posts: 20136000, 20136071

Yes this is the " 997 upgrade" lol.. ...I can assure you the improvement was due to the fresh Driven DT40 .... Yes I have seen some real doozies !!!

Thanks @Porschetech3 for the detailed insights! I just did these parts update two wknds ago on my 2/98 c2, and immediately upon changing it, my oil pressure throughout the rev range increased (after engine fully warmed). At idle it is consistently at 1.5, rest of rev range (at least .5 to 1 bar higher). The original spring was not broken, it had 121k miles on it. At the same time I also changed to 15w-50 (from 3600 miles old 5w-40) If this pressure increase didn�t come from the parts updates, why have others also have similar positive experience? It would be interesting to merge this new post with the existing post about this parts upgrade. Thanks again for this!

It's possible that fixing the squealing sound helped with oil flow. The squealing sound would have been caused by turbulence in the flow of oil. Turbulence would create both drag and flow instability. So fixing one problem, may have inadvertently helped the flow.

Quotes source post: 20136159

I think most people will feel the same as you and is a Placebo Effect...wanting to believe it is an "upgrade" and misinterpreting the real root cause of the Improvement ( if any) ..Your improvement came from draining out 3600 miles 5w-40 and filling with fresh 15w-50.. Many run Mobil 1 0w-40 which is barely a 40 weight and quickly shears down to a 30 weight, then a fresh fill will give a slight improvement + a Placeco Effect.....this has people believing the "upgrade" was responsible......and the Cycle continues

Good to know @Porschetech3 ! I hope others find this thread before they go swapping out this part. 10yrs back when I owned my first 996 of ten yrs, I never heard of this update either..