Italdream: I sent you a PM.

 

What is the reason why one tailpipe soots up and not the other? Any consequences? What to do if the answer is yes to the above.

Thank you

cai

 

They should soot up at the same rate. If one gets darker a lot quicker than the other, then at least the mechanic would have a direction as to what bank of cylinders might be suspects.

 

As previously stated below, cars do burn oil at different rates. Some none, some a little, etc.

So what is considered normal? A lot argued with the manufacturers that his or her car was burning oil: to put into a term "Oil Consumption Issue" (OCI).

So, how do you establish OCI? Most manufacturers would agree with you that if you are using 1qt per 1,000 miles, then you have a case of an engine with a case of high OC. They in turn will replace/warrant the engine.

I can confirm that Nissan uses the 1Qt/1K miles as the gauge. Now, if you are using 1qt every 900 miles, I am not sure who wins: the consumer or the dealer? I bet the decision will be based on your relationship with your dealer.

BTW, I bought a brand new 370Z with high OC. The dealer pulled out the then 'secret TSB', performed the test, and finally I was given a new engine. I then sold it back to the dealer, walked across the street to the Porsche dealer and bought the 997. Once a Porsche-guy always a Porsche-guy.

 

On the 997.1, I believe there is also something about the way the AOS dumps air back into the engine that causes the right bank (left exhaust) to soot a little more. So it can be nothing at all (most likely), or a sign of a failing AOS or the dreaded scored cylinder (very, very rare). If you have a .2 car then I'm not so sure.

 

Most except Porsche. Rennlist member "Edgy" has an -06 C2S that he bought brand new. It's consistently burned a quart of oil every 600 miles and Porsche says that's within tolerance. Barely since I think they draw the line right at 600 miles for a quart. For my -09 C4S I get between 1,500 and 2,000 miles on a quart.

 

Not to steal the thread but had not heard that explaination for the sooty tail pipe before. Mine tends soot up more on the left side, although both sides show soot after more spirited driving. Is the issue correctable by installing a new AOS or just a consequence of the design of the AOS ?

 

Hmmm? Are you sure Porsche draws the line at 600 miles? I thought Porsche started the 1,000 mark then Corvette/Chevy followed, etc. I suspect of Porsche said 600 miles is within tolerance, then I would think the high-range is way above 600.

If I were "Edgy" and burnt oil at 600 and 600 is Porsche's limit, I would have insisted for a new engine. I'm a Rennlist member and should probably check this out.

 

I agree. No way I would accept that.

 

Assuming this is the same Gundo, where is he when we needed him? Gundo posted this for the MY2007 model and let me share. Pretty unreal as far as oil consumption. Has anyone checked the manuals that came with our cars? 1.6Qt/622 miles!!!! If my arithmetic is correct, Porsche allows about 391 miles/qt of oil consumption!!!

 

Yes, i did post that - i found it unreal as well. 1.5 liters per 1000 km or 1.6 qts per 622 miles.

At the time, my car, 2006 C2S with 10k ish miles was burning 1 qt per 1000 miles and I found it unacceptable.

Dealer reaction was to monitor, and every fill of oil had to be at their shop with a measurement before and after.

Net net, I was within tolerance. Made a big stink, they were ready to spend some money to diagnose my car, then PCNA - who reads these boards regularly - found the oil consumption survey I started and the many posts. My service agent casually mentioned that PCNA reads the boards, then denied my claim and the their offer of compression and leakdown tests for the oil consumption issue.

All of that is well behind me now, I still have the car, and I use about 1qt per 2k miles at this point. I do like the points about hard driving, as I definitely used more when taking to the track and driving hard. I currently 26k miles.

Good luck, but based on what I've seen, you are within spec and will see no help from PCNA nor your local dealer's service shop.

Gundo

 

Interesting,...I have always checked with the car idling,...never switched off?

 

Really? Let me be the first: RTFM wherein R= read and M=manual.

 

Hmmmm. What does your manual say about this?

 

The manual for his 997.2 (2011 C4S) says check while idling. The Porsche bulletin from post #40 above was for 997.1. Here's what the 997.2 manual says:

Conditions for measuring the oil level
1. Vehicle stationary.
2. It is important to ensure that the vehicle is horizontal for correct oil level measurement to occur.
3. Engine must be at operating temperature (at least 140 °F/60 °C).
4. Engine must be idling.