Instrument Failure

[RF5BPilot]

Every few months, the oil pressure gauge on my 2003 996 drops to 0 with a warning of an instrument failure.

I previously asked the dealership about it. They said there wasn't much to do (because it is working by the time I can get it there), but if it did it again, bring it in right away so they could read the error codes to see what to fix.

It happened again today, I took the car in right away, they checked the error codes which confirmed that there was a problem somewhere in the wiring, the sender or the gauge. Nothing that we didn't know before.

So, their best guess is that it is the sender and will replace it tomorrow under warranty (it's under warranty through April 28th). However they stress that if it doesn't happen again before the end of warranty, any gauge replacement, etc., won't be covered.

The car is a CPO, so there's a small chance that it might be covered later under the CPO extension. But at the moment, it seems as if even though the problem started under warranty, I may get stuck later. A little frustrating.

Any ideas?

(There has not been any clear event that seems to trigger the failure. It's not as predictable as just going over a bump.)

[Loren]

We have seen a few sender failures - so that would be the most likely failure.

[RF5BPilot]

We have seen a few sender failures - so that would be the most likely failure.

Thanks Loren. It is happens rarely and doesn't last long (almost feels like a flakey ground....but it's not particularly repeatable like you often see with loose grounds). It would simply be my preference that, whatever it is, it gets handled under warranty (esp. as it started happening while under warranty).

btw, happening or not, I have appreciated a warning from the system that it's an instrumentation issue rather than a genuine drop in pressure.

Yet.....if it's the oil pressure sensor, how can the system tell it's not the engine? Are there two sensors or another source of oil pressure info?

Edited April 4, 2008 by RF5BPilot

[Loren]

Well, if your oil pressure really dropped to zero - your engine would not last long (minutes likely). Oil pressure is primarily mechanical - so it either works or it doesn't. It would be very unusual to have oil pressure actually come and go.

Both wires go to the cluster - the sender unit is grounded to the engine case.

I do not know of any other oil pressure sensor - so as you said it is likely that it is the sensor or the wiring. As I said before, several folks have had similar problems so it is very likely your problem is the same.