sdmooney

I have a 2000 996 convertible c4 that is registering low oil pressure. Car has 24k miles, and uses 5w40 mobil one synth. When car warms up, oil pressures at speed are 3+, but when idle and warm, oil pressure drops below one, nearly zero, and the oil light flickers, and turns off. After warm, normal driving puts oil pressure at 2-ish. Took to a porsche mechanic (indy) and they said that they feel that the problem is a sensor and not that the oil pressure is really low. Said the car runs great, and that if the oil pressure was really that low, they would notice a problem (knocks, rough idle, etc). Going to have it checked out again in a couple of weeks after an upcoming move with a dealer. Wondering if anyone else has this problem and whether this should be a concern. I don't appear to have an oil temp gauge, so I can't comment on that. Water temp is fine.

Any thoughts appreciated...

Doug Donsbach

Your best course of action at this point is to replace the sensor. If the problem persists, connect a mechanical gauge. If that shows low pressure...then things get expensive.

sdmooney

Thanks, hopefully won't be too big an issue.

ivangene

+1 for sensor (and change oils )

sdmooney

I haven't been on this board long, but I can tell you I'm not going there! Anyway, thanks for the advice, going to get it check out shortly.

pl

just changed my oil to 15-10, now it's 2bar idling, it used to be around 1bar when using 0-40

sdmooney

Just wanted to follow up on this, let folks know what the problem was (see above). Thanks for the advice. I took my car in in early may (after moving/shipping car across country).

So, it turns out it was low oil pressure. Replacement of the sensor didn't work. Since my 996 (2000) has low miles (25k) there was some thought that maybe the oil system needed to be cleaned out. So we flushed the system and moved to a thicker oil. It helped a bit, but oil light would still flicker on when engine very hot. Anyway, after some investigation -- not a car guy so might get this wrong -- it turns out a spring in the oil pressure relief valve was broken. In the end it cost about $900, but he fixed a couple of other things. Kind of frustrating since the oil pressure relief valve was an easy fix.

However, this has been really frustrating because right after I got it fixed, the cable that opens the boot lid over the engine and is attached to the lever next to the drivers seat broke! Gotta take that in now...

Thanks again for the advice...

sdmooney

also - oil pressure now at 5 bar when cold and about 1.5 bar when idling...

perryinva

Thanks for following up, not many ever do that, and it is really appreciated. Now I'm curious as to where this oil pressure relief valve is located. Those are good pressure numbers now.

sdmooney

Not sure, I waited outside the shop. But it only took the mechanic a few minutes to fix it, and he didn't put the car on the lift.

sdmooney

Also - to clarify, he charged me $80 to replace the spring. Said he sees this problem occasionally.

ivangene

wow,
thanks for follow up and good info !

wross996tt

so for more...the relief valve is #11 and the spring is #13...

ShaneSaw

I'm dealing with the same issue on my 2000 carrera and i've found this old thread. I called Boardwalk and they said they can't find a "pressure relief valve/spring" on the diagram. The drawing above is for a turbo and mine is non-turbo. Does anyone have the part number for the spring?

Thanks in advance.

fbgh2o

I would try either of the following

996.107.127.53
996.107.125.51 which has been superceded by 99710712501

I pulled them off http://dcauto.gotdns.com/illustration/index/454857735 which seems to indicate they are part of the oil pump assembly.