Oil on top of engine

Hello knowledgeable Porsche friends. Today I was replacing the alternator on my 2002 C4S manual. I was fortunate enough to get the alternator out without too much of a struggle, but once out I could see oil pooled on the top of the block in the depressions. It is dirty oil so I am not thinking a cracked oil filler tube. Pictures are attached. Has anyone else encountered this and what might be the source of the oil? While the alternator is out I might as well attend to the source. It has not leaked enough to be noticeable on the dipstick or drip on the garage floor so it would seem small (but maybe not “minor”). Thanks in advance for your comments and advice. Overview with alternator removed. Closer view of the pooled oil. Many thanks again. Cross posted

This will be my DIY for oil pressure sensor (aka oil sender unit). I will have to gather all the info and this will take shape eventually. For now, putting up stuff that I have, once I find the pics and edit, I will update. SYMPTOMS: Symptom was while driving (at a stop, after car warmed up fully), get error oil pressure fault. The oil pressure gauge reads zero on left (analog needle), and the digital readout (if you configured your cluster to show it), shows dashes, no numbers, and at bottom of right display, orange oil symbol flashes for about 15 seconds. Shut the car down, and watch the flashing oil symbol. Once the symbol flashing turns off, you start car and as if nothing was wrong at all. Once I replaced the oil pressure sensor , the temp showed much lower, and the oil pressure (while fully warm, at idle) was showing much higher. With defective switch, my pressure at idle was at about 1.0 or 1.1 sometimes. With new switch in, at idle (same conditions), pressure was showing at about 1.6. Big difference. DIFFICULTY : I would rate complexity at 3 out of 10. HOWEVER , due to space limitations, it was like doing dentistry on a patient, through the patient's anus. Literally, on a turbo, you have just enough space to wiggle fingers, blind, while you try to remove 2 torx screws, then yank sensor out, replace and install it back in. It was a hassle for sure. That is unless you want to remove the front of the car, and play with reassembly later on. From what I remember, FSM also recommends doing the way I did this. About sensor location: The sensor is #8 on diagram. standing at front of car, facing it, sensor is located on passenger side, front of engine. It is to the right of the pulley, under the drive belt. The flashlight illuminates the location. You can barely see it from front. You will be able to see the two E-torx screws , don't remember size, prolly e8 or e10. Once you have the intake hose off, you can squeeze your arm between valve cover and the rad hose. TIP: - If you are left handed, it will suck for you. Your fingers must be facing towards sensor. - Huge help - wet the inside forearm of the arm you will use, with motor oil. Don't ask me what grade, lol. There, I used 5W40 castrol. It will help the arm slide past valve cover, so fingers can get to the bolts. Small socket driver needed to get into that space. Another tip is don't remove electrical connection from sensor until you remove the screws. Then, the sensor with its metal bracket, will slide out of the hole, and you can play with removing the connector. Small flat tool needed to pry the inner tab, from what I remember. Gentle. If you break the connector retainer tab, the whole connector may slide off over time. You will be back to same symptoms, even though sensor is good. Recommend as a 2 person job. One to do work, while other one assists with camera if you have, giving drink, and encourage you not to quit. As anything in life, if you determine yourself not to quit, you will be successful. Well, here is the partial stuff...... DIAGRAM OF OIL PRESSURE SENSOR LOCATION (along with locations of other sensors - for your reference): REPLACEMENT PROCEDURE (these pics are unedited, but you will get some sense of it all , until I get time to prepare and annotate correctly). For now, trying to help folks out so posting what I have as is:

On my 99 c4 this was the seals between the oil cooler and the block. I also had some antifreeze showing in the same area. I drained the oil and coolant, put a shop vac on the expansion tank to pull some vacuum (it is an oil to water cooler :-)). On my block the seals where 2 different sizes. I managed to avoid any cross contamination somehow 120,000 miles later and still tight and dry This was in Nov 2012 so what I remember is vague, except for how cold it was :-(

Thanks for the DIY with pictures. I did this today and you are not kidding about it being a tight blind space. Getting the old one out and disconnected was no problem. Getting the new one in was a pain in the butt. I did it myself but could have used a helper to hold the camera. I wouldn't even attempt this without a snake camera. I also would not do this again. Whatever they charge for this is worth it. It sucked bigtime. Hopefully, it cured my issue. We shall see! Thanks again for the DIY!

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No problem. After this it took my will away to do proper pics diy. Seemed easy but the location sucked azz . Glad you did it. I'm sure will he good to go. Just update us. take care. Quote:

Oh and it's an E10 socket for the bolts holding the sensor on.

500 or so miles later and no sensor error message. I believe this cured my issue. 🤞🏻

Congrats. You have successfully completed another panamera maintenance item. Great job.

Aaaaand it’s back. Ugh. I honestly think it is some kind of electrical fault caused by interference. It went off in the same geographical area of a road where it always went off before. I think radio waves or something is interfering with the electronics and causing the fault.

Did you buy a genuine Porsche sensor? From my experience, non porsche electronics never hold up. I always ended up having g to buy genuine, so stopped buying after market. Too much Chinese junk that works for a month, then it's toast. The genuine parts are tested for longevity and cycles, that's why they last much more. checking just in case. I'm sure you already know.

Yes, it's a factory part. Now my front struts are sagging overnight. I already replaced a parking sensor as well. Sigh. 33K miles and so many problems. I love the car but I can see it is going to be a challenge to own.

Just an FYI - this is a 20 minute job on an N/A car - still blind, but way more room to work!!

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Quote: I was hoping for that. :-) By the way. I see a lot of people replace the oil pump due to this. It does not make sense to me? I have never ever heard of an oil pump failing intermittently, they always fail gradually over a long period of time with the oil pressure steadily declining, or is the Porsche pump different?

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Some replace fuel pump as means to pd. Oil pump is expensive to fix. You pray it doesn't come to that on a ptt. porsche pump no different. Oil pressure sensor 1st culprits. On turbo, its a pita but doable. Quote:

Another bookmark for me ... GREAT WORK, Ciaka ...

Thank you so much for this post, I just did mine. If you remove the cover below the engine and have a second person watching and guiding you, its really not that bad. Apart from the time lifting the car and removing the cover, the actual job replacing the sensor took no more than 30 minutes. Additional information: - there is a pin on the front of the electrical connector you need to push to get it out. - there is an O-ring between the engine and the metal part behind the sensor that does not come with the sensor, remember to buy that beforehand.

I had oil pressure issue after I dropped my car @ Porsche for AC Diagnostic. Here is what they charged. NO I did not let them do it >>> report OIL PRESSURE FAULT. Comments: DURING VEHICLE SCAN NOTICED FAULT CODES PRESENT FOR OIL PRESSURE SWITCH OPEN CIRCUIT. INTERMITTENT. SOMETIMES WHEN VEHICLE IS RUNNING OIL PRESSURE FAULT WILL ILLUMINATE ON INSTRUMENT CLUSTER AND 0 PSI OF OIL PRESSURE ON ENGINE OIL PRESSURE GAUGE. IF VEHICLE IS RE STARTED SOMETIMES SENSOR WILL WORK. SUGGEST TO REPLACE OIL PRESSURE SENDER AND PERFORM OIL CHANGE. VEHICLE ANALYSIS LOG WITH THESE FAULT CODES CAN BE SEEN. Repair Estimate: $1265.84 >>> For my 2016 PAN4, replace oil pressure is very straight forward as shown in the attached doc.

The preasure sensor 1 and 2 what are they and what do they do ? I'm getting low oil presure fault. changed sensor (8) but still the same error. the oil heats up, and i got oil preasure sensor fault as well. clueless on what to do next, change the solinoid ? Change the oil pump or can sensor 1 or 2 be at fault, what are the parts numbers for them ?

Just did my oil pressure sensor last weekend. Work Great. Thank you, Ciaka.

Great write ups - thanks all. Just completed this on my 2012 Panamera GTS. As others have said getting the sensor off is pretty straightforward but getting the new one on is an unpleasant experience. After giving up on trying to get the sensor in place for the bolts I decided a new approach was necessary. I slid the LHS sensor and housing onto a M6 15cm bolt then got this a little into the LHS bolt hole. The extra length gives you more space to manipulate and turn the bolt. You can also see the LHS hole while you’re doing this. Having got this long bolt in place you can slide the sensor and housing along it to the block in reasonable position to fit the RHS bolt. I found that the electrical connector was making the sensor and housing sit too high on the RHS. Using a snake camera I was able to see the correct position to get the bolt in. I then firmed up the RHS bolt a little to keep everything in place, removed the long M6 bolt and fitted the correct LHS bolt. For info this was a right hand drive car and LHS/RHS above is when looking from front to the back. Also I let the oil settle overnight before starting and there was no leakage when the sensor was removed. The sensor replacement cured my problem.

Hey @johanvanderwalt , do you happen to have a part # or measurements of the o-ring needed between the engine and metal piece?

The oil pressure sensor bracket o ring part number for the work on my UK 2012 Panamera GTS was 99970757540

@Pandaman1 Awesome! Thanks a ton for the reply!

After replacing the sensor mine was cured for a while, then came back. Next I replaced the Solenoid in the oil pump with the same result, cured for a while then came back. I now replaced the ECU and loaded new software - it also made no difference.