My car is a 2004 996TT 6-speed manual. The " System failure (With the Oil Icon)" Red warning light comes up everytime I go over 110 MPH !!! The oil pressure needle goes all the way down to zero and then back up again. The dealer changed the whole cluster thinking that it was a faulty one. They retrieved a 9121 oil pressure fault stored in memory. The wiring was ok, but they replaced the cluster as per workshop manual. I got the car back and went back home, well low and behold I started getting the "system failure" again with the drop to Zero pressure, plus a "check engine light" !!!!!. Took it back and this time nothing bad was recorded/stored in the memory.
Is the ECU bad????( Not recording the events) Is the oil pump bad??? Engine bad????

Any ideas appreciated.

Black996TT

 

I don't own a 996 so this is just an idea. Maybe the wire going to the pressure sensor is flapping in the 110mph wind. Maybe the connector at the oil pressure sensor is loose, or one of the wires rubbed against something and touches metal somewhere to get grounded, or loses continuity when the wind moves it around. The oil pressure sensor is usually located near the oil filter. I would find the sensor, check the connector, and trace the wiring back looking for any damage, etc.

 

Anyone else ?????? Any ideas???? The service technician will be reading the thread.
Thanks.

Black996tt

 

I believe I had the same issue. oil pressure gauge would go to zero, come back up, go to zero...

Dealer replaced the the oil pressure sensor. That fixed it.

 

Hmm.. I didn't mention that because I assumed the dealer wouldn't have changed the whole cluster before changing a $3 pressure sensor.

 

Same here.

 

I just had the same issue. Engine oil malfunction code, have read the codes yet. just curious is it an oil pressure sensor?

 

Oil pressure sensor (Porsche call it a pressure sender) are known to fail and it is the cheapest thing to replace for troubleshooting purposes. Part# 99660620302 about $65.00 and not a bad job to replace but tight spot....

 

Thanks for the info.

 

Common problem. a search here revealed that the wire connection at the oil pressure sending unit is most likely the cause of the intermittent oil pressure gauge fault. If that doesn't fix the fault replace the sensor.

I can't believe that the dealer would replace the cluster without checking the sender and the sender connection.

 

That would be the first thing that would pop in my mind. What dealer?