Oil Consumption

[Herman]

I am a new Porsche Owner. I bought a 1987 911 Carrera Coupe a couple of months ago. The PPI showed excellent results from the Leak-down test (i.e., 2% to 3% on all). I live in Colorado and drive the care about once every two weeks. It is winter and I don't use it as a daily driver. It is more of a garage queen. I have two questions. First, what is an acceptable rate of oil consumption (i.e., is 3/4's of a quart every 1000 miles okay)? I have read many opinions on the subject. Second, I have noticed that it smokes briefly (i.e., <30-45 seconds) on start up ONLY after it has sat for two solid weeks. Is this normal or do I need to be concerned?

Other than the typical these questions, the car is great. I replaced the DME relay under the drivers seat and cleaned up a few other annoying little problems.

Thanks for your help.

[Rot 911]

Under Porsche guidelines 1 qt. per 600 miles is considered within specs so 3/4 qt. per 1000 miles is more than acceptable. Yes all 911's will puff out some smoke on start up. Has to do with the flat six engine layout. So everything on your car sounds ok!

[Herman]

Kurt, thanks for your response. Does the fact that it sits for two weeks at a time have any affect on the amount of smoking that I should tolerate at start up?

[Craig]

Hey Herman,
I live in Ft. Collins too! We should get together for a cruise up the Poudre sometime!

As for the smoking, mine seems to smoke more if it has sat for a while (all the more reason to drive it!!)

Email me if you get a chance!

cperry@waterpik.com

Craig

[john walker's workshop]

keep a close eye on oil use. with the carrera valve guide/stem seal problems, some cars use a quart in 300 miles, and don't seem to smoke much for it. that's 10 qts in a 3000 mile oil change interval. i just drained oil on a fairly low mile 87 and it had about 1/2 the amount that normally comes out. i bought my 87 cab from a guy who never checked his oil and it spun a rod bearing. an overhaul and a crank would have cost him at least 10K. got a screamin deal.

[Herman]

Thank you for the reply. I hope that doesn't happen to me. I pay close attention and check the oil level frequently (i.e., make sure that it's half way between the marks). I'm much more neurotic with the car than I am careless. It never smokes when I drive it - just a little on start-up after sitting. Otherwise it seems to be working and driving quite nicely.

[Jdub]

Yes but John, you are like a huge Bass on the lake bottom just waiting for the Chub and minnows...they walk into your jaws!!!

Anyway, my 2cents is that often it is the level of the oil that will seem to indicate out of spec oil consumption. That is, Pcars seem to like a certain oil level that, once breached, causes oil consumption (to you, the owner, anyway) until the car "finds" the oil level it likes best.

Try filling the oil to 1/2 way on the dipstick then let the car find its level. It may "stick" around 1/4 or so at the dipstick. Then again, it might keep going down.

Jw

PS: How dearly I remember getting an original 1976 Eddy Merckx frameset (I met the man!) when I worked at the bike shop: all it needed was a new down tube: brazed it in, repaint to Molteni oragne and voila; I got the bike but not the legs!

[emcon5]

Also, the max consumption number does not include leaks.

Something I found out when I had my engine out, just because your car doesn't leave any oil spots on the garage floor, doesn't mean it doesn't leak oil.

The top of my engine looked like the Exxon Valdez, but my garage floor is spotless (under the 911 anyway).

Tom

[scedmonds]

I use a quart of Castrol GTX 20-50 weight every 500 miles. That's certainly a cheap price for the ride it gives me . . .

Mine will smoke on start-up after it's been sitting, which is 3-4 days a week due to my travel schedule.

Enjoy your "new" P-car!

Cheers!

C.

[nostatic]

I recall reading that the flat 6 orientation causes oil to seep when the car sits, thus the smoke on startup. The longer it sits, the more oil there is to burn.

Molteni orange would be a great color for a 911. Kinda between Gulf and Signal (maybe a bit darker). I still find it entertaining that Merckx doesn't report their head angles on their frames...it's "proprietary".

[josh912]

Originally posted by nostatic
I recall reading that the flat 6 orientation causes oil to seep when the car sits, thus the smoke on startup. The longer it sits, the more oil there is to burn.

Is that why 912s burn oil too?

[nostatic]

Originally posted by josh912


Is that why 912s burn oil too?

I believe any horizontally opposed engine (912, original VW, etc) would have the same characteristics. Not sure if Subies do this though...

[johnd]

my 93 subaru legacy with 250k original unopened engine miles and no tuneup, uses about a quart every 2000miles, but it does have a tiny drip out of the front crank seal. My 84 911 uses about a quart every 1000miles, no smoke, no leaks. The legacy runs as good as new, just a few more squeeks and groans though.