Oil Starvation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

insite · 11-04-2011, 05:15 AM

another note on oil starvation:

there is a piston/spring assembly inside the oil pump that varies oil pressure with temperature. when the car is cold, it's designed to increase the pressure to around 100psi. once the car warms up, it backs off to 'normal'.

my car was running about 16-17psi (hot) at idle, which seems low to me. on a hunch, i ordered a new piston & spring. interestingly, the new piston has a chamfered edge whereas the original piston had a sharp edge. this leads me to believe that porsche suspected some binding of the piston assembly in some instances......

at any rate, with the new piston / spring installed, the car is now at 23psi hot. i never logged the oil pressure under load, so i have no idea what (if any) effect it has on pressure at RPM, but i certainly feel a little better. loss of oil pressure at temp is a big concern in the M96. anything that reduces the risk to that end is a win in my book. cost is less than $20 and you can do it in 5 minutes when you change your oil.

FYI, part numbers are:

Piston: 997.107.125.01 ($ 5.00)
Spring: 996.107.127.53 ($10.00)
Gasket: 996.107.123.50 ($ 2.00)

jaykay · 11-04-2011, 05:44 AM

Yes I remember this thing really wondered about what it actually does. I thought it was at the front of the engine and really hard to get to. There is an old post on here with a schematic. No idea on how search for it.

I seem to recall that it appeared to modulate the volume oil delivered by the pump. Good to know that there is boost in oil pressure when starting up. Guess you guys with an accusump could perhaps watch the accumulator modulate depending on what air pressure you put in there to test this thing??

insite · 11-04-2011, 06:26 AM

very easy to get to. it's on the bottom of the oil pump facing downward. it really does take only a minute to change. you're right about the accusump; the first time i fired the car up w/ the accusump, i though the gage broke!

schematic photo of oil pump (change items 5, 25 & 26):

insite · 11-04-2011, 06:30 AM

here's an actual pic. spring guide bolt circled in red.

RickyG512 · 04-04-2017, 07:19 AM

Quote:

Originally Posted by insite

very easy to get to. it's on the bottom of the oil pump facing downward. it really does take only a minute to change. you're right about the accusump; the first time i fired the car up w/ the accusump, i though the gage broke!

schematic photo of oil pump (change items 5, 25 & 26):

Hi there, I've got the 3 new parts, will the engine drain oil once I remove the bolt? Does the engine need to be empty of oil before I do this? Thanks

911monty · 04-04-2017, 07:39 AM

Quote:

Originally Posted by RickyG512

Hi there, I've got the 3 new parts, will the engine drain oil once I remove the bolt? Does the engine need to be empty of oil before I do this? Thanks

No and No. The oil is in the sump and has to be picked up by the pump. Just oil the piston before you install.

ChrisZang · 11-04-2011, 08:33 AM

VERY interesting!

Would you think that this could be the possible solution to my "low oil pressure on the track" problem? http://986forum.com/forums/general-discussions/29545-low-oil-pressure-track.html

In a nutshell: Oil pressure drops mid-session

Thanks
Chris

Quote:

Originally Posted by insite

another note on oil starvation:

there is a piston/spring assembly inside the oil pump that varies oil pressure with temperature. when the car is cold, it's designed to increase the pressure to around 100psi. once the car warms up, it backs off to 'normal'.

my car was running about 16-17psi (hot) at idle, which seems low to me. on a hunch, i ordered a new piston & spring. interestingly, the new piston has a chamfered edge whereas the original piston had a sharp edge. this leads me to believe that porsche suspected some binding of the piston assembly in some instances......

at any rate, with the new piston / spring installed, the car is now at 23psi hot. i never logged the oil pressure under load, so i have no idea what (if any) effect it has on pressure at RPM, but i certainly feel a little better. loss of oil pressure at temp is a big concern in the M96. anything that reduces the risk to that end is a win in my book. cost is less than $20 and you can do it in 5 minutes when you change your oil.

FYI, part numbers are:

Piston: 997.107.125.01 ($ 5.00)
Spring: 996.107.127.53 ($10.00)
Gasket: 996.107.123.50 ($ 2.00)

insite · 11-04-2011, 08:43 AM

Quote:

Originally Posted by ChrisZang

VERY interesting!

Would you think that this could be the possible solution to my "low oil pressure on the track" problem? http://986forum.com/forums/general-discussions/29545-low-oil-pressure-track.html

In a nutshell: Oil pressure drops mid-session

since you're seeing a drop on straights as well as in the corners, i think it's absolutely possible.

also, not sure if you have an S. if you don't, upgrade to the S oil cooler. hot oil gets thin & pressure drops.

The Radium King · 11-04-2011, 09:21 AM

here is an option to get an x-51 style baffle in your car for a few less $$$, and without having to modify ...

New Oil Baffle - Pelican Parts Technical BBS

Col986 · 04-07-2015, 04:06 AM

Quote:

Originally Posted by insite

another note on oil starvation:

there is a piston/spring assembly inside the oil pump that varies oil pressure with temperature. when the car is cold, it's designed to increase the pressure to around 100psi. once the car warms up, it backs off to 'normal'.

my car was running about 16-17psi (hot) at idle, which seems low to me. on a hunch, i ordered a new piston & spring. interestingly, the new piston has a chamfered edge whereas the original piston had a sharp edge. this leads me to believe that porsche suspected some binding of the piston assembly in some instances......

at any rate, with the new piston / spring installed, the car is now at 23psi hot. i never logged the oil pressure under load, so i have no idea what (if any) effect it has on pressure at RPM, but i certainly feel a little better. loss of oil pressure at temp is a big concern in the M96. anything that reduces the risk to that end is a win in my book. cost is less than $20 and you can do it in 5 minutes when you change your oil.

FYI, part numbers are:

Piston: 997.107.125.01 ($ 5.00)
Spring: 996.107.127.53 ($10.00)
Gasket: 996.107.123.50 ($ 2.00)

I know this is a very old thread, however I looked back through all the old posts to see what upgrades I should do on my 2004 986 S (550 anniv) whilst doing the IMS upgrade.

I ordered the above mentioned parts, only to find they were identical to what was already installed. Not sure when the the upgraded parts became standard.

BoxsterSteve · 04-25-2015, 06:59 AM

Quote:

Originally Posted by Col986

I know this is a very old thread, however I looked back through all the old posts to see what upgrades I should do on my 2004 986 S (550 anniv) whilst doing the IMS upgrade.

I ordered the above mentioned parts, only to find they were identical to what was already installed. Not sure when the the upgraded parts became standard.

I bought these parts too... less than $23 after taxes, a cheap DIY. Can't hurt after 15 years, I figure.
If I recall, these upgraded bits came onstream in 2003 or 2004, so I'm all in putting them in my 2000.

Fyeganeh · 07-28-2015, 05:51 AM

Quote:

Originally Posted by insite

another note on oil starvation:

there is a piston/spring assembly inside the oil pump that varies oil pressure with temperature. when the car is cold, it's designed to increase the pressure to around 100psi. once the car warms up, it backs off to 'normal'.

my car was running about 16-17psi (hot) at idle, which seems low to me. on a hunch, i ordered a new piston & spring. interestingly, the new piston has a chamfered edge whereas the original piston had a sharp edge. this leads me to believe that porsche suspected some binding of the piston assembly in some instances......

at any rate, with the new piston / spring installed, the car is now at 23psi hot. i never logged the oil pressure under load, so i have no idea what (if any) effect it has on pressure at RPM, but i certainly feel a little better. loss of oil pressure at temp is a big concern in the M96. anything that reduces the risk to that end is a win in my book. cost is less than $20 and you can do it in 5 minutes when you change your oil.

FYI, part numbers are:

Piston: 997.107.125.01 ($ 5.00)
Spring: 996.107.127.53 ($10.00)
Gasket: 996.107.123.50 ($ 2.00)

So I know this is an old thread, but I was wondering about people's opinion on doing this "upgrade" or refresh on an oil pump piston, spring and gasket. Has anyone tried this? Did it help? If you haven't done it, what is the consensus on doing it? Could it hurt?

Any thoughts would be appreciated.
Fred

steved0x · 07-28-2015, 07:34 AM

Quote:

Originally Posted by Fyeganeh

So I know this is an old thread, but I was wondering about people's opinion on doing this "upgrade" or refresh on an oil pump piston, spring and gasket. Has anyone tried this? Did it help? If you haven't done it, what is the consensus on doing it? Could it hurt?

Any thoughts would be appreciated.
Fred

I did it on my 2000S, but since I don't have any oil pressure monitoring I couldn't say whether it helped or not.