2007 Porsche Cayman – What a Low Pressure Oil Light Looks Like

Let’s call this a Public Service Announcement-
Many of us will have never seen what annuciations occur on a Cayman 987 dashboard when you have low or no oil pressure. To revisit history, the Porsche Cayman, when released in 2005, did not have an oil pressure gauge (or a dipstick!). A quick review of the internet tells me that this state of affairs started with the 986 Boxster released in 1997, so this will not be news to many of you. Apparantly, many folks have subsequently added supplemental gauges.

The Cayman also does not have the universal “oil pour can” symbol on the gauge face. I find this unfortunate, as if you are diligent, when you get in your car and turn the key to “run”, you can pause for a second and make sure that all the critical dash lights are operable. Of course, they typically go off when you start the engine. But, again, you can’t make this check with the Cayman regarding oil pressure.

So what the Cayman does have is a simple on/off sensor mounted at the top of the bank 1 cylinder head. Once the oil pressure reaches a certain pre-set value, the sensor goes from “grounded” to “open”. I know, I tested a used one to confirm. I just applied some air pressure to the open hole in the end of the sensor and saw it’s resistance go high. I do not know what the setpoint is in psi/bar.

So the Owners Manual has a chart of annunciations. There is what I will call a Text Message block at the bottom of the dash, in the center. It gets used for all sorts of messages and info. Tire pressure. Oil level. Etc. Etc. What occured to me, after my very expensive engine rebuild, is that there is really no simple way to see if/how the message block would annunciate in the event of low/no oil pressure, other than a chart in the Owners Manual. So I set up a test. I ran a test lead from the sensor male connector to the wiring harness female connector. I ran a wire in parallel from the male connector, which I could connect to ground as a test. I started the car. Of course, right before you start the car, the sensor is grounded but there is no indication on the dash, I guess to avoid a nuisance message. I started the engine, then I took the extra lead and grounded it. I heard a tone from the dash, similar to that which sounds when you hit one of the standard setpoints. And the message block annuciated. A picture is below. Note that the handbrake was set and I had a PSM warning because I had disconnected the battery right before the test. That explains the PSM symbol being illuminated. I am not sure if the red exclaimation point was illuminated because of the low oil pressure or the PSM warning. Whatever, you can see how the message appears.

Hopefully you will never see this message but at least you know what to look for. As to whether your low pressure sensor is even working, I can’t offer anything simple except to perform a test like I did. Maybe there is something in PIWIS that can test this without so much effort, I don’t know. Anyway, there you have it.

CAUTION- If you see this warning message on your dash, it is best to shut your engine down immediately. It should be obvious that if you have lost oil pressure, serious and terminal damage to your engine will shortly follow. And engines are expensive! So seriously, pull over and shut down the engine in as short a distance as possible. If it is safe, get out and look for evidence of oil on the rear of the car or on the ground. That will be a bad sign but it should settle your mind that you need to call for a tow. After the engine has gone through its mandatory 5 minute (or so) wait, you can check the oil level on the dash gauge. If no bars are showing, that is also a bad sign and probably warrants a call for a tow. One exception that might exist is if the light came on during some spirited driving with heavy cornering. It may be that the oil in your sump was pushed to one side and uncovered the oil pickup tube. Not a great situation but if you think this may be the issue, use the Function stalk on your car to cycle through to the oil level indication. If you are seeing one or more bars, you can try restarting your engine and see if the dash message comes back. If it does not come back on, you might be able to get away with a sedate drive to somewhere where you can buy oil to add. Of course, there is always the chance that you will find no evidence of an oil leak and the dash gauge shows plenty of oil. So you might be lucky in that it is just a failure in the sensor circuit. In that case, you might be justified in trying to drive to a more favorable place. But this scenario could also be the result of the (rare) failure of the engine oil pump. If you hear “clatter” noises from the engine, shut the car down. It’s a calculated risk. Just remember, Hope Is Not a Plan. If you are Hoping that you can make it home with the light on, DON’T. At least not until you have fully evaluated the situation.