hi all
i have a 04 cayenne S, going thru 1 litre of mobil 1 5w-30 every 1000km, plus or minus, is this normal>? i know CTT burns that much, but mine is only a S.

also when i change my spark plugs, the one in cylinder 6 is totally worn out and turned black...is that an indication of oil burning? any reason why thats happening?
thanks

 

IMHO - abnormal (or "abbynormal" for the Young Frankenstein fans..) although Porsche probably considers this within the "normal" range (1 liter/600 miles?)

My '06 with 71,000 miles uses no discernable oil between 10,000 mile changes. I am using M1 0W-40, so it's possible your oil is a bit thinner when the engine is fully warmed up which could increase use a bit.

FWIW - A difference in appearance of one plug ALWAYS indicates "something is going on." The plugs should look identical.

I can't see where excessive oil use (assuming something like weak rings in that cylinder or a worn intake valve guide) would cause more wear on the plug, but it certainly could cause it to look darker then the other plugs. If the gap is noticeably wider then the other cylinders something odd is going on.

What is your idle quality like? Notice any lope to it or miss? To really tell what's going on in cylinder 6 you probably need a compression test followed by a leak-down test. That will tell you if that cylinder has a problem.

If the compression tests do show a fault (more then 5%-10% difference in compression from the other cylinders) the leak down test should give a clue where the problem is (the mechanic listens for leakage at the valves and at the crankcase.)

If those tests show no faults, then I'd be suspicous of the coil or plug causing the excessive wear on the plug (has this happened with repeated plug changes?) And I'd look elsewhere for the reason for the oil use (clogged or damaged PCV system perhaps?)


At that point - it might be worth having a boroscope used to look at the inside of the cylinder (think of an engine colonoscopy) and see if there is a scratched bore.

Good luck!

 

thanks for the detail reply!

as for ride quality, the idle is pretty stable, a little bit below 500, and 2 days ago, there was a misfire in cylinder #6, so i replaced all the spark plugs, and turns out cylinder 6 spark plug was black and kind of worn out, so far, the car hasnt shake yet, and i noticed its smoother than before.

the car seems normal except its burning oil, my mechanic said its going to be a huge job, so he suggested just drive it for now, and add oil as it required.

 

If I may ask, why are you using 5W-30 oil? I've heard 5-40 and 0-40, but never 5-30.

 

i have been using mobil1 5w-30 for the last oil change..does that explain why it is burning oil?? if so, i better stop, i use it cus i got some extra ones that i havent used...i know the manual says 0-40 is the recommended one..maybe i should try using thicker oil?

 

i am using a thicker oil and it appears to be greatly reducing the amount that is burnt between oil changes,

 

What kind of oil? 10w30 is that the thickest?

 

I don't understand your question. Do you understand how oil viscosity works? The bottom number is the base viscosity of the oil, W means "winter" (not weight - a common misconception) and the upper number means the oil performs as a 40 weight oil would when it gets hot. That doesn't mean it IS 40W when it's hot - it is whatever the viscosity of a 40W oil thins out to when it's hot.

Anyway - look at Mobil-1. They make a 0W-40. That is an approved Porsche oil.

 

I have been running 15w50 and it seems to be helping with amount burnt between changes.