In January of 2016 I purchased my first 911. A 2009 997.2 C2 with only 13.8k miles and a 2 year 50k certified Porsche Warranty. I have put 2.5k miles on it and the check oil level warning came on.

I understand that is normal. I added first .5 liters of A40 approved oil and it rose one bar, then added the balance of the liter and brought it up to mid range on the oil level indicator. The next day I drove the car about 5 miles and out of curiosity I sat and checked the oil level and was surprised to see it dropped 1 bar. I drove it another 5 miles and repeated the oil level check and found it had dropped to the minimum level, or yet another bar. I let the car sit to see if there was an active leak. There were no signs of leakage. I checked the garage floor at home and it is as clean as a whistle.

Should I just add another quart?

 

Something is wrong here. Flat six do consume oil but not at that pace.

You should use the approved oil Mobil 1 0W40 for all addition.

Check the condition of your exhaust pipes.
Check if there is any whitish/blueish colored smoke coming out of them.

The difference between the lowest bar and the highest is usually one quart.

I suspect that your car has not been used and run enough and as a result may have developed some internal pitting and corrosion on the rings and cylinder walls.

Also, driving it 5 miles is not enough. You need to bring the engine to full temperature which will help with the cylinders and rings. However, because of the rate at which you are consuming the oil, you should keep a close eye on the dashboard, water temperature and oil temperature and bring a couple of oil quarts with you.

Driving the car often should improve the loss of oil. If it does not, you may have to use the CPO warranty and have the cylinders inspected.

Do not over-rev the engine and stay around 3,000 RPMs, at least at the beginning.

Good luck.

Yves

 

Thanks! I added the oil to a cool engine last night and got the highest reading after the engine warmed up (through idling and stationery) I wonder if that played a role in a false reading? No blue smoke noted, but I will look again and run that test drive.

 

I find the difference to be a bar or two depending on how long it ran, how long it sits before checking it and sensitive to the slightest non level ground.
I also have a 2009 and use no oil between changes at 10K.
Could just be an error in the way you are measuring compounded by some slight usage.

 

My oil usage is similar to Cerbomark. I've got a 2010 C4S as my DD, and given my 50-mile round-trip daily commute, I change oil every 6 months (roughly equal to every 6k miles). In 3 years of ownership, I've never had to add oil in between oil changes. For what's worth, I always wait until my oil temp hits about 250F before I check it, and I always make sure to stay on TOTALLY level ground (generally in my garage after a commuter run).

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My car used to go through some oil when it was new - seems that after 20K it has stopped doing that. I usually check it when I come home and park - at that point the engine is as hot as it will get and the garage is flat. If it is below the middle mark, I'll add 1/2 quart and check it again the next time I drive and return.


You'll notice that the reading can vary - for example if you switch off the engine, then switch on and measure again. For that reason. I don't shoot for the top mark, but rather somewhere above the middle - you don't want it over-filled.


This is also worth noting from the manual:


If the vehicle is used for repeated short trips, and
consumes a normal amount of oil, the engine oil
measurement may not show any drop in the oil
level at all, even after 600 miles (1,000 km) or
more. This is because the oil is gradually becoming
diluted with fuel or moisture, making it appear
that the oil level has not changed.

The diluting ingredients evaporate out when the
vehicle is driven at high speeds, as on an expressway,
making it then appear that oil is excessively
consumed after driving at high speeds.

 

You have to be sure you are consistent in when/how you measure the oil level.

I am not familiar with the 997 engine but if you can check it cold do so after the engine has sat overnight and be sure the car is on level ground.

It is not unusual to have the level down a bar or two when the engine is cold. Once up to temperature the oil will expand and the reading will move higher.

If you check the oil hot do so after the engine has been up to temperature a while and after the engine has been off a while. With my 2002 Boxster a good time to check the oil level is after I have filled up the gas tank.

When you check the oil level the level will likely be higher than when you checked it cold.

It is very rare, unheard of, for an engine to lose large amounts of oil with no leak sign and with no smoking.

If you are accurately measuring the oil level and finding it is "dropping" by large amounts in a very short time this strongly suggests the oil level sensor/system is malfunctioning.

While you certainly do not want to run the oil level too low, not even low enough to get the low oil level (or pressure!) warning, you do not want to over fill the engine either.

The only way I know to check the proper functioning of the oil level sensor/system is to perform a "by the book" oil change which after a proper drain interval has the tech adding a known quantity of oil to the engine and confirming the oil level sensor/system reports the correct oil level.

 

I have a 2009 C2 Cab and typically have to add about 3/4 of a quart every 400-500 miles. I bought the car with 20k miles in Feb '15 and now have about 26k in mileage. I have kept a spreadsheet of mileage and how much I have added since I have owned the car.

There is something in the manual that says adding oil periodically is within their engineering tolerances.

Though what the OP mentioned does not seem right. I also try to always check the oil consistently when the oil temp is around 200. I don't ever recall my oil temp getting to 250.

 

I don't recall ever seeing my oil temp over 200, maybe I need to drive it harder? Also I need to check the manual, I didn't know you could check it cold. I check mine in the garage as well after a longer trip.

 

You cannot check a 997.2 cold - at least not by any normal means.

 

Yep, it will tell you the temperature needs to be higher.


I have found deltas in the level based on temp. (~175ish vs 200) I assume this is difference in viscosity based on temp.


I have learned to only check the oil when it is at or about 200 degrees and not any cooler.

 

Three-quarters of a quart of oil every 450 to 500 miles is border line excessive oil consumption. IIRC Porsche says the oil consumption can be be as much as one liter per 1000km or approx. 1 quart every 600 miles.

There are things that can contribute to higher than normal oil consumption. Lots of idling or very high RPM operation are two, the big two.

There is another thing to consider. The AOS fitted to these engines suck.

Thus my theory is for a number of "oil burners" the real problem is not due to an engine that uses the oil that gets into the chambers via the normal routes, past the rings or past the valve seals/guides, but instead is delivered through the intake due to an inefficient AOS that simply allows too much oil vapor to pass through it. Oil vapor that is routed to the intake and burned.

Since the engine warmed up there will be no smoking.

However, I couldn't recommend an AOS replacement for an AOS that is not manifesting any of the signs of failing on the strength of my theory.

 

I really don't do a lot of idling and rarely take the car past 4500 rpms. I also do not have any smoke issues which I understand would be indicative of an AOS failing. I am however curious as to my oil consumption.

I have no idea whether the POs properly warmed the car or drove it in short spurts where it did not warm up and this may have affected break in. Since I have owned the car I always seem to take the long way to where I'm going and it always gets a proper warm up when it goes out. I don't necessarily warm it down too frequently however.

 

You've hit on a question that I've had. Is there a good cool down procedure that should be undertaken after a spirited drive or is simply pulling into the garage and shutting it off sufficient (after checking the oil, of course!)

 

for at least the 99.2, PAG recommends:


Stopping Engine

-Turn key back to position 3.

- Do not stop engine immediately after hard or
extended driving. Keep engine running at increased idle for
about two minutes to prevent excessive heat
build-up before turning off engine.


I usually just let whatever song I'm listening to finish.