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Hi guys,

So I am in need of your wisdom, as I am at the end of the road here with any and all ideas as to why I have extensive oil burning issues. The dealer has provided very little assistance and just says it can be anything. Below is a list of all the background, details, and testing to date. I hope that one of you uber techies can assist.

1. Car is a 2006 Cayman S 6 speed.

2. Burnt absolutely no oil from new till about 50k miles. All of sudden at 50k miles started to burn 1 quart per 600-800 miles. Heavy carbon deposit on rear bumper and tailpipes.

3. Oil changes intervals varied from 1 - 2 years with roughly 15-20k miles between oil changes, as per Porsche maintenance placard. Car was daily driven.

4. No previous technical issues with car aside from waterpump failure at roughly 45k miles.

5. I did some research and changed my AOS, as this seemed to be a common culprit in many cases. This had no impact on my oil burning consumption.

6. Had dealer do full inspection on car at ~60k miles. Dealer indicated that all cylinders were scoped with no scoring found. Cylinder 4 had minor oil pooling, but no cause could be determined. Plugs had light buildup of carbon. Pressure test done on cylinder 4 with loss of 6 PSI at 90PSI, vs cylinder 5 with loss of 5 PSI at 90 PSI. Crankcase and exhaust pressure all within specification. Dealer indicated they didn't know what was wrong and to just continue driving car.

7. Oil and filter sample results were sent for analysis around the same time. Oil was 18 month old and had 15.5k miles on it. Concerning results came back as follows.
a. Aluminium 10 ppm.
b. Chromium 3 ppm.
c. Iron 51 ppm.
d. Lead 11 ppm.
e. Silicon 21 ppm.

7. Car recently, at 80k miles, started to surge a bit on startup and throw engine code P0421 (warm-up catalyst efficiency below threshold bank 1). I drove the car like this for a few days as it was completely drivable and I couldn't make it into the dealer. I then parked the car for 4 days, after which when I started the car it ran really rough, was misfiring, and threw codes P0302 (cylinder 2 misfire), P0421, P0431 (catalyst efficiency bank 2), P0300 (random misfire). The car was underivable and I towed it to the dealer.

8. Dealer found all 6 spark plugs completely black (carbon) and dry. Found oil pooling in cylinder 2, but not in other inspected cylinders. Further inspection found intake header and MAF covered in oil, which required cleaning as engine wasn't operating at higher RPMs. Plugs all replaced, oil changed, and oil cleaned from intake system. Dealer stated that they are unsure as to what caused this, and to keep on driving car. Please note that I recently replaced the plugs, so these fouled plugs only had 20k miles on them. I also replaced all the ignition coils about 4 months prior to this event.

9. I took the car home and it ran perfect, but oil is still burning. I actually always used Mobil 1 0W40 per Porsche spec, but after this last issue asked the dealer to switch it to Amsoil Euro Spec 5W40, as I heard a lot of guys stated it didn't have high consumption like Mobil 1. I checked the oil level and it dropped 1 bar within 60 miles, so I am not sure I am having any different luck with a different oil type.

10. I then recently parked the car for another 6 days and started it without any issues. It ran fine with no hessitation or surging. I also re-rechecked the AOS by opening the engine oil cap and there is very little vacuum, so seems like AOS might be okay. I also noticed that if the car is parked for maybe 1 day, upon startup I get a plume of white smoke but it subsidies after a few minutes to a very small amount.

I don't really know what to do next as the dealer thinks it might the piston rings, and feels that air intake system contamination could have been due to over pressurization of crankcase and sucked in by PCV valve. Dealer did not do any other tests or suggest any other course of action aside from what I mentioned. Dealer just says to keep on driving it like this, which obviously doesn't seem like a very reasonable statement. Unfortunately I only have one dealer in the city and can't get a second opinion aside from aftermarket shops.

I was just thinking maybe I need to do a leak down test on each cylinder, as I can't come up with any other ideas. The other thing is that all 6 plugs are contaminated with carbon, but if I had a specific cylinder issue then wouldn't I just have that cylinder's plug contaminated? Also having heavy oil contamination in the intake system seems like maybe something else is causing all of this and then equal distributing oil contaminated air into all 6 cylinders? I would greatly appreciate any assistance.

Regards,

VadRad
I know it's been awhile, but did you ever determine what caused your oil consumption?

I have an '06 Cayman S that has similar oil consumption. Thanks!
 

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I know it's been awhile, but did you ever determine what caused your oil consumption?

I have an '06 Cayman S that has similar oil consumption. Thanks!
Usual dump the problem and run.. when people started suggesting the AOS be replaced he got resistant to the idea, it wasn't jiving with whatever disaster he'd envisioned.. so he left. His last visit here was July 2017.

You see this a lot in forums - someone just looking for confirmation that what they've already decided to do is the right thing to do. All sorts of forums - some not even vehicle related. If they don't get agreement with their already made decision they leave and go somewhere else where they hope the crowd is friendlier (or stupider.)

As far as your '06 - has the AOS been replaced? That would be the first thing to do. If that doesn't help it's time to scope the cylinders and pray that you don't have any cylinder damage.
 

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Besides bore scoring another thing to consider is valve seals. My '05 had very high oil consumption - 1 qt every 700 miles - which I resolved by replacing the engine. The tear down of the old engine did not reveal any bore scoring but I did have burnt valves on a couple cylinders and bad valve seals.
 

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After reading all the older replies no one talked about the Used Oil Sample Analysis. This within itself is a Great troubleshooting tool!! He did a UOSA early on but didnt say anything about the results he posted.
Aluminum 10 ppm the avg is 4 ppm
Chromium 3 ppm the avg is 1 ppm
Iron 51 ppm the avg is 9 ppm
lead 11 ppm the avg is 2 ppm
Silicon 21 ppm the avg is 7ppm
Based on these results he either needs a new motor or tear down existing motor and rebuild. Used Oil Samples dont lie!! Every Porsche owner should be pulling samples on every oil change which will show the health of the motor or its demise......
 

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After reading all the older replies no one talked about the Used Oil Sample Analysis. This within itself is a Great troubleshooting tool!! He did a UOSA early on but didnt say anything about the results he posted.
Aluminum 10 ppm the avg is 4 ppm
Chromium 3 ppm the avg is 1 ppm
Iron 51 ppm the avg is 9 ppm
lead 11 ppm the avg is 2 ppm
Silicon 21 ppm the avg is 7ppm
Based on these results he either needs a new motor or tear down existing motor and rebuild. Used Oil Samples dont lie!! Every Porsche owner should be pulling samples on every oil change which will show the health of the motor or its demise......
Could not agree more. Money well spent. I just got my latest back today: Aluminum: 3, Chromium: 0, Iron: 4, Lead: 0, Silicon: 2. Blackstone Labs.
 

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After reading all the older replies no one talked about the Used Oil Sample Analysis. This within itself is a Great troubleshooting tool!! He did a UOSA early on but didnt say anything about the results he posted.
Aluminum 10 ppm the avg is 4 ppm
Chromium 3 ppm the avg is 1 ppm
Iron 51 ppm the avg is 9 ppm
lead 11 ppm the avg is 2 ppm
Silicon 21 ppm the avg is 7ppm
Based on these results he either needs a new motor or tear down existing motor and rebuild. Used Oil Samples dont lie!! Every Porsche owner should be pulling samples on every oil change which will show the health of the motor or its demise......
Just the silicon and iron numbers indicate a worn out engine. Aluminum and Silicon is the bore. Iron and Chromium is the rings. I would imagine his compression is probably quite low in at least 1 or 2 cylinders.
 

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Usual dump the problem and run.. when people started suggesting the AOS be replaced he got resistant to the idea, it wasn't jiving with whatever disaster he'd envisioned.. so he left. His last visit here was July 2017.

You see this a lot in forums - someone just looking for confirmation that what they've already decided to do is the right thing to do. All sorts of forums - some not even vehicle related. If they don't get agreement with their already made decision they leave and go somewhere else where they hope the crowd is friendlier (or stupider.)

As far as your '06 - has the AOS been replaced? That would be the first thing to do. If that doesn't help it's time to scope the cylinders and pray that you don't have any cylinder damage.
No, but the AOS is definitely the first suspect. I think bad valve guides can also cause this.

Was just curious as to how it worked out for the OP in case there was something new to learn.

Thanks for your advice!
 
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