Oil pressure too low and fluctuating idle speed when stationary

  • Good evening to all,

    I was actually hoping to be spared this topic, but I'm worried that engine failure is on the horizon.

    The 996 FL Carrera 2 now has 139,500KM on the clock and so far it has never let me down!!!

    On the last trip four weeks ago, however, the warning light went on "oil pressure too low" after a sporty chase up the Großglockner.

    The car came fresh from service at the time and with new 5W40 Castrol Edge Titanium.

    I immediately turned off the engine and let it cool down! Then checked oil and supposedly it was fart dry! Added a liter on it and it was back to maximum. The subsequent start was an absolute shock because a large blue cloud of smoke was emitted!

    Quite leisurely I am then the pass "rolled down" to spare the car! After that, peace in the case and I drove 31 more passes and 3200 KM far without any incidents or increased oil consumption!!! Also the morning starting was completely unspectacular and without any clouds!

    Today I drove after some short distances times again and have but yesterday evening half a liter of oil filled up.(Since 2500 Km).

    A heavy blue cloud of smoke came towards me and honestly it did not sound really round because the engine or a pump had to plow quite! Also I could vibrations and a felt unrounder idle!

    I am then cautiously go because no other signs of damage have been noticed!

    The pressure fit as soon as the engine was warm and everything was as it should be! Until I came to a red light and found that the idle speed was quite high at 1100 rpm! ( Otherwise always 800 revs and bullet clean running).

    After an hour break I went again and the rough starting or the vibrations were again felt but after driving off again gone!

    I know that many will now say "use the search function" but that has honestly brought me no further!

    Although I have a very high confidence in my independent Porsche workshop I fear that this can not really help me!

    The background is that the message with the low oil pressure occurred during an Alpine tour a year ago and then disappeared without a trace as this time.

    The workshop could not make sense of it, therefore my "skepticism" before the assessment of the otherwise very appreciated workshop.

    Thanks for your help and especially for reading this rather long description!

    Maybe you know which damage pattern fits the diagnosis!


    Nic van D

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  • Blue smoke means that oil is being burned. I had this once with a BMW E39 and usually these are the usual suspects. Let the workshop take a closer look at the valve cover gasket and the crankcase ventilation / oil separator. In case of emergency, an independent Porsche workshop should find the fault, the damage pattern does not sound like rocket science, get a second opinion if necessary. You can still worry about the piston and cylinder, but for now, don't panic.

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  • First check your spark plugs to see if they are dirty with oil.

    I think that your oil separator has a quirk and so the oil consumption is to explain.

    Throttle valve also take a look and check for deposits because of the speed increase.

    Do not always assume the worst.

    Good luck

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    Machen ! Nicht sabbeln.

  • Okay thanks already for the tips!

    I'll report as soon as I know more details!!!

    Please feel free to post any other "clues" or guesses!

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  • ...I would also first guess the oil separator due to the smoke, the fluctuating idle can also come from a defective LLM and the oil pressure problem point to a broken sensor.

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  • In the Boxster, the engine is mounted the other way around. There, the oil pressure switch/oil pressure sensor is on the other cylinder bank. In the 996, seen from the rear, there is a picture screw on the left bench at this point. If you are unsure about the oil pressure: buy a VDO pressure cell and round instrument and check if the display in the car is correct. With mine spinnt the pressure box - seems öffters occur. Have now ordered a new one.

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    996 C2 3,6L 320PS MJ2002

    (kein Facebook, kein WhatsApp)

  • Hello all,

    short update on my workshop visit yesterday:

    1. readout of the error memory showed that at some point a one-time error was stored on bank 2.

    2. the hissing came from a micro hairline crack in the thread of the oil cap whereby foreign air was drawn. (Other cap on it error was gone)

    3. the fluctuating RPM was also eliminated by the new oil cap and by clearing the fault memory.

    4. the problem of low oil pressure after brisk driving can only be caused by the sensor and should be replaced.

    5. the blue clouds of smoke emitted due to the low oil pressure are probably the result of the defective oil separator.

    (6). I have noticed for some time that it started very badly / bumpy despite a full battery. Here the workshop said that the starter motor is probably gone, which is not uncommon.

    We have now agreed that I do some test drives on the weekend and we look in the coming week whether the error on bank 2 occurs again or not.

    If not then we would fix findings from points 4-6, which would cost about 4000 - 4500 € including assembly and renewal of all peripheral parts.

    According to the workshop he runs engine silky smooth, loses no water and shows no abnormalities so engine damage unlikely.

    Let me know what you think.

    Greetings go out.

    Nic van D

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  • (6). I have noticed for some time that he started despite full battery again and again very bad / bumpy. Here, the workshop said that the starter is probably gone, which is not uncommon.

    :pfeil: here it could also be useful to check the wiring. Have schön öfferes read that there was/are cable problems.

    I don't know if it's easy to get to the starter. If yes, if necessary ne second battery directly to the starter via starter cable and check if it gets better. Then possibly again the second battery directly paralel to the normal battery.

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    996 C2 3,6L 320PS MJ2002

    (kein Facebook, kein WhatsApp)

  • Hello Nic

    interesting. Actually, nothing that does not count to the topic of wear. What surprises me now is the price tag. k:thinking:

    That seems too high to me, even if that were here in CH. Do they remove the engine? Must not be at least for the oil separator, went with me so.

    If so, then the price is clear, you should then but other wear parts such as hoses, oil filler neck, rubber gearbox bearing, Variocam guides, ignition coils, plugs, etc. etc. have the same exchange. Then it drives probably again so far. Before possibly times the running surfaces in the engine on grooves let examine let.

    Good luck!



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  • So the total is definitely including engine removal and add-on parts like hoses and gaskets.

    These parts:

    Rubber gearbox mountings, Variocam guides, ignition coils, plugs

    are not included to my knowledge or are not included in the price.

    By the way, I asked in how far the "too low oil pressure" or the sporadic oil separator in the form of blue clouds has an influence on the engine or its durability.

    The workshop then said that this would be qausi without hesitation.

    Of course, I ask myself the question of whether I do not simply continue to drive with the current condition and simply check the one or other time more oil or refill.

    Please don't get me wrong, I am the last one who would not do everything for the durability or preservation of the 911, but if this would be a pure precautionary measure then you have to ask yourself if you can not use the money better.


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