Oil Sensor Failure?

[montegoblue]

Hey guys! Driving my C4S today the "oil failure" code came on, losing the reading on the oil pressure gauge -- lasted for about 30-60 seconds and then the pressure reading came back to normal. It did this one more time before I came home. I check the oil level and it's OK. Is this a bad sensor?? or could this be something more serious that needs immediate attention? I asked because this is a car that I don't drive very much and also CPO warranty is almost done. Thanks

[Loren]

Best double check it with a PST2 or PIWIS tester.

[montegoblue]

Hey guys! Driving my C4S today the "oil failure" code came on, losing the reading on the oil pressure gauge -- lasted for about 30-60 seconds and then the pressure reading came back to normal. It did this one more time before I came home. I check the oil level and it's OK. Is this a bad sensor?? or could this be something more serious that needs immediate attention? I asked because this is a car that I don't drive very much and also CPO warranty is almost done. Thanks

[montegoblue]

Thanks Loren but do is the car safe to drive to Porsche dealer; any ideas of what may be wrong off the top of your head?

[Loren]

If it comes on again during your drive to the dealer - you should likely have it towed.

Could just be a bad connection or loose wire but there is no back up for oil pressure.

[whall]

I don't mean to muddy the water, but there are two failure display modes concerning engine oil pressure.

The first and least problematic is the OBC warning with an oil can icon and the verbiage: "Failure Indicator"....which means: "Oil pressure indicator is faulty. Have the fault remedied at an authorized Porsche dealer".

The second and potentially the more serious is an low oil pressure "idiot light" in concert with the OBC oil can icon with the folowing verbiage: "Engine oil pressure too low"....which means: "Stop immediately at a suitable place, measure oil level with the on-board computer and, if necessary, add engine oil". The low oil pressure idiot light has the ultimate vote, being essentially an "on/off" switch....some pressure/no pressure.

If you just got the OBC warning without the idiot light, as Loren says, you may have a bad oil pressure sender, or a bad connection at the sender.

If you got the OBC warning and the idiot light - with sufficient oil in the engine, things get more complicated and potentially more expensive. You could still just have a bad oil pressure sender, but it would be the better part of valour to have your car flat-bedded to a shop for a definitive analysis. In any event, a PST2/PIWIS can find out if you had an actual low oil pressure event. Like many tattle-tails, that information is stored in the DME.

Bill

[Yoops Racing]

I just went through this 2 weeks ago...scared the bichezit out of me. Another oil sending unit failure - oil pressure dropped then went way high then fell way low......seems to be a common issue

[montegoblue]

I agree -- the light that came on was the less ominous "failure indicator". The funny thing is that I drove the dickens out the car today and nothing came on... ran perfectly with new Potenzas-- awesome :)

[deckman]

My car is at the dealer now (see other post on ignition switch). I've had something like this happen numerous times in the 1.5 years I've owned it. I'll be driving along and suddenly oil pressure needle drops to 0 and a warning indicator "oil failure" appears. It lasts for 5 to 15 seconds and then all is back to normal. I had the dealer check it over the summer and they couldn't find anything wrong. I guess it didn't leave a code behind. I just asked them to check it again but the service rep doubted they would find anything. I even suggested it was the sending unit. WTF? The car tells me it's being starved for oil and they shrug their shoulders? The car comes off of CPO coverage the 26th.

[deckman]

I just had this happen again about four times in quick succession over the course of two miles and about 3-4 minutes, with each warning lasting about five seconds. Of course when I had it at the dealer just before the CPO expired they couldn't find anything wrong. I plugged my OBD II reader in and there are no codes.

[Loren]

I just had this happen again about four times in quick succession over the course of two miles and about 3-4 minutes, with each warning lasting about five seconds. Of course when I had it at the dealer just before the CPO expired they couldn't find anything wrong. I plugged my OBD II reader in and there are no codes.

A standard OBD II reader will not find anything for an "oil failure" - OBD II is emissions.

You need to find someone with a PST2 or PIWIS tester that can read the sensors state.

[tac27]

I just had this happen again about four times in quick succession over the course of two miles and about 3-4 minutes, with each warning lasting about five seconds. Of course when I had it at the dealer just before the CPO expired they couldn't find anything wrong. I plugged my OBD II reader in and there are no codes.

I've had a similar experience. I've taken it to both the dealer and an indie with the sam results: no code, no problem detected, and 'unable to replicate' during a test drive. I'm assuming that the dealer and indie are using the appropriate system testing device (the PST2/PIWIS vs. a OBD II).

The 'idiot' light doesn't illuminate, just the message on the screen about an indicator failure. I have also seen the pressure guage needle rapidly bounce from the 0 to the 5 for a few moments without any message or indicator light. Each occurence, I curb and manually check the oil; its always near the top notch on the 'stick.

Edited March 17, 2009 by tac27

[Benjamin Choi]

this happened to my c4s yesterday. it literally reads "failure indicator" with the oil can/fuel icon on the OBC to the left of the words. i can't say if my pressure guage went haywire at the same time because i didn't look at it at all.

replaced oil pressure sending unit per suggestions here and in other threads. dealer cleared the fault code too.

should be fine now! thx all.

[kpl]

For those do it yourselfers try this: remove the electrical connectors to the oil pressure sending unit, clean the connections, reinstall after adding a glob of dielectric grease to each contact on the sender. Wipe a little of that same grease on the connectors after you snap them back together. Worked for me. I take it as an oversight on Porsche's part that these connectors are not sealed from the elements.

[deckman]

I am trying to do replace the unit right now. It's super tight down in there and the wrench I am working with is cut down to about 5 or 6". the sensor on my car is in on very securely. I can't seem to get enough leverage to loosen it. I'm tempted to take pliers to the top of the unit and try to get it loose but am afraid I'll just crush it. Then it would still be stuck and I wouldn't be able to drive the car.

Anyone replace this and have a similar problem?

[fpb111]

I am trying to do replace the unit right now. It's super tight down in there and the wrench I am working with is cut down to about 5 or 6". the sensor on my car is in on very securely. I can't seem to get enough leverage to loosen it. I'm tempted to take pliers to the top of the unit and try to get it loose but am afraid I'll just crush it. Then it would still be stuck and I wouldn't be able to drive the car.

Anyone replace this and have a similar problem?

I have not replaced the sender in the 996 yet. You might try something I have done in the past when in situations like this. You have a cut down wrench, can you put it on the sensor so the you can reach it with a long dowel and push it in the correct direction to loosen it? If so put a V or U shape in the end of the dowel to capture the wrench - push and wack the other end with a hammer. The shock should loosen it.

[deckman]

I am cross posting on Rennlist since that is where the original DIY was.

I did finally get the unit loose using a wrecking bar wedged against it and using my body weight against it. However....

This is getting comical. I rigged a wrench like the OP did, basically cutting open a box wrench and shortening it so it would fit in the confines. I'd take a pic to show you but....it is now stuck on the bolt attached to the underside of the sending unit. It wiggles up and down and left to right, but I can't pull it off to save my life. I don't really know what to do about it.

I tightened the unit back up and went to get new tires today. I am driving with a wrench in my engine bay. But believe me it isn't going to fall out.

[Dharn55]

OK folks here is the tools that makes this simple. A 19mm Crowfoot wrench. Use this with a 3/8" universal, extension and socket wrench and the removal is simple.

Jack up the car, put in a jackstand, remove rear right wheel, slide the crows foot wrench in from the bottom, you need the universal to get the wrench on due to the angles around the spark plug shield. A little twist on the socket wrench and it loosens right up. the just spin it out from the top, spin the new one on and tighten it down with the crowfoot. Really easy and fast.

Got the crowfoot at NAPA, here is a link

http://www.napaonline.com/NOLPPSE/(S...cf19m&Ntk=Part Number&N=0&Nty=1&D=ncf19m&Dn=0&Dk=1&Dp=3

Probably available from other sources. Made the job incredibly easy.