excessive Oil consumption Boxster S
 

I own a 2000 model Boxster S with about 110,000 km's on the speedo.
It seems to be using a lot of Oil. Am using Mobil 1.
On a trip recently (actually 2 trips) a total of about 1000 km's ,I used 2 liters of OIL!
Is that normal? or what's the problem?
There is NO leaking of Oil or smell of oil whilst it is in my garage or when the engine is hot. NO oil leaks on the floor of my garage at all!
Any ideas? Cheers and a great 2011 to all.

I also have a 2000 S, currently with 26,000 miles. It burns very little oil...I have to "top off" the oil once or twice between 6,000 mile oil changes (less than a quart of oil added in total). If it's not leaking on the ground then it will have been burned during the combustion cycle or leaking into the cooling system. No clouds of smoke? Oil clean (not the color of coffee)? Just thinking out loud here...

Have an '01S
 

with close to your mileage. That is excessive. Mine has never had oil added, only changed.

So assuming no leaks, what do the plugs look like, what does the exhaust pipe look like, what does the throttle body look like?

It is either leaking or burning.

It's them Tazoilion-devils that you got there in Aussie who be a steal'n your oil when your not looking. No really what mike said...leaking or burning.

Tex,
Has the car suddenly just started this oil consumption?
Was the oil at max level before the trip?

Several things spring to mind:
1) Has the coolant level remained normal and clean - no intermixing of the two? If the coolant has a frothy coffee coloured consistancy, you have a problem.
2) If the oil is old (10,000km) it really needs replacing - especially Mobil 1 0W40 which is reported to go out of spec quite early in its lifespan.
3) If the engine had done a lot of short trips, followed by a long trip, the accumulation of moisture in the oil generated by the short trips is "boiled off" on the long trip which suddenly looks like sudden oil consumption - though 2 litres in 1000 km is a lot....
4) Your AOS could be starting to fail, allowing oil to be dragged up into the combustion process. Check the throttle body for oil accumulation or remove the oil filler cap when the engine is hot and idling and if the cap is difficult to remove (vacuum) the AOS is suspect.
5) Get under the car after a run with a torch and see if there really are no oil leaks, especially where oil can drip onto a hot exhaust and burn off very quickly. Cambox and spark plug tube leaks are a favourite

Replacing the oil with (say) a slightly heavier 10W40 or 10W50 full synthetic oil (I use Shell Helix Ultra) and checking the level over the next 1000 km would be a good start too.

I recall reading something (might have been the owner's manual) that spoke to the variations of oil level over time. It said that frequent short trips cause fuel dilution of the oil, which would increase the level or mask the degree of oil consumption. It went on to say long high speed trips burn off (vaporize) the fuel dilution and make it appear that the oil was consumed on the trip.

Personally I don't worry about oil too much unless I see a leak or smoke out the tailpipe. A continuing pattern of 500 miles/qt would get my attention though. My recently acquired 2000 S doesn't appear to use much if any oil and it has over 100k miles on the odometer.

Short trips where the AOS is pushing oil into the intake
-- or extended sitting where the oil might work its way passed the rings.

Either case you would see puffs of smoke on startup.

check your coolant to be sure there is no intermix.

if you suspect too much oil being burned in normal driving
you can check your compression.

You can also check the intake and see how much oil residue is
in there -- it could be your AOS (or aos control) is acting up and its
pushing oil into the intake all the time.

mike

Oil consumption
 

Hi All,
Many thanks for your advice ,will check all the suggestions and report further down the track, Cheers TEX

For my car 2003S with 62M plus miles consumption is pretty much 1 quart per 6,000 miles or so . This is in city driving.

I found the section of the owner's manual that talked about oil consumption.

http://i19.photobucket.com/albums/b1...xsterhp003.jpg

I completely agree it "may" be the use of Mobil 1 (assuming 0W40)...try a heavier weight, as suggested. You are heading into summer there and temps will rise. I've read articles by Jake Raby and Charles Navarro suggesting the rings in the M96 are "loose", contributing to fuel getting past, into the oil; a heavier weight would discourage this. I only drive my '02 in fair weather, use 10W40 high quality synthetic and never need to top off.