Elie

did it eventually turn off the engine?

Sneaky Pete

Yes...it would not idle on it's own without adding some fuel.

Imo000

If the engine idle drops too low, so will the oil pressure. You can easily get fixated on the oil pressure when the problem is a very low or no idle. The knocking noise can be from the very low idle too however you need someone that knows what they are doing look at the car. They don't need to be 996 experts.

Ahmet

I agree the issue doesn’t sound like an internal engine problem if you can keep it running with the gas. I’d suggest plugging in an OBDII reader to have some idea what’s going on before you make the trip to the mechanic.

Elie

Turned on the car today, and it seems when i'm driving the oil pressure is stable, but when idling the oil pressure varies between 1 and 1.3 roughly, not sure if this is normal...

Imo000

What is your idlining speed?

Elie

i was parked...

relinuca

Starting with MY2000, the 996s were fitted with electronic throttle pedal assemblies, and throttle position was electronically integrated into the DME system. Even infintesimal changes in throttle position are communicated. Your symptoms seem to be prompted by lift off...that may be significant.

Time for a Porsche DME systems guru to get invloved.

relinuca

Sneaky Pete

When the car is parked what are the RPM's? Under 500?

Macster

Based on my experience that's about right.

Porsche doesn't call out a hot idle oil pressure, just oil pressure at some higher RPM.

So the way to know if hot idle oil pressure is ok is if at hot idle the low oil pressure light doesn't come on. That and that the oil pressure at high RPMs is ok. The assumption is that if the oil system can deliver oil sufficient oil pressure at say 5K RPMs with hot oil it can handle the oiling needs of an idling engine just fine.

My WAG is there is something amiss with the engine -- but not oil pump or oil supply related -- that causes the RPMs to dip and the engine to eventually stall. As the engine RPMs drop the oil pressure drops -- gear driven oil pumps do not like too low RPMs, they do not work very well at too low RPMs -- and you see the low oil pressure warning. The knocking is probably not so much (if any) oil pressure related but the normal noises of an engine running below its specified idle speed.

You need to get the car to a qualified tech for diagnosis. I'd check for any pending DTCs. The symptoms sort of sound like some of the ones my 02 Boxster engine manifested when a VarioCam solenoid/actuator started acting up. The engine RPMs would drop dramatically and the engine would sound very bad -- very sick -- but RPMs would rise with some throttle and the engine would sound ok again. After I turned off the engine and restarted it the symptoms went away and I drove the car home 30 miles away. I am not recommending you drive your car any!

Get the car flat bedded to a shop for a pro's diagnosis.

5CHN3LL

Another assenting opinion that something (perhaps a vac leak) is causing the stall at idle, which you're interpreting as a loss of oil pressure and the engine turning off. Getting to a mechanic is always a good idea when the engine's stalling without your assistance.

Elie

One more shot for the owners, my engine sound on camera, not sure if you can make anything out of it, but probably worth it: this was recorded after 45 minutes drive in traffic, max speed 60 km/h...

https://www.youtube.com/watch?v=irTZ...utu.be&html5=1

Also excuse my lack of knowledge, what is the VAC problem?

Thanks all for your feedbacks, i'm getting back my 2nd car tonight, so no more driving the porsche until pb is fixed...

Best Regards,
Elie

fpb111

Sounded fine.
VAC = vacuum. 5chn3ll is referring to a possible vacuum leak causing the stall at idle.

Ahsai

Is the "knocking sound" there in the video? It sounds fine to me.

Elie

No knocking sound, the only time the knocking happens is when the rpm/oil pressure are getting very low, just before the engine stops, or just before it recuperates with some gas...

I guess i have what i need now for the diagnosis...all valuable inputs, i'll start working on it soon, and will let you know the results...