Puzzled by low oil consumption

[DARISC]

I've put 20k miles on my RoW SC since I bought it 2 years ago. I just checked my oil (fully warmed up, on level surface, motor idleing, after idleing 1.5 min., just like I always do and the stick was wet to midway between the high and low marks.

Last oil change was 3k miles ago, after which the stick was wet to the very same point that it is now and I haven't added any oil since that time, .

The car is my daily driver, 99% city, and I drive it hard (to or near redline usually at least once per day - and I'm addicted to downshifting for the sheer fun of it). Every time I check the oil, usually once a week, I get the same reading.

When I bought the car the PO told me he did his own oil changes every 3k miles. I asked him how many quarts it used over that period. None, he said. Really, I said. Really! he said. I didn't believe him but that is apparently the case.

The motor's got 194k miles on it, original rings and valves. The only thing done to the motor was a cam regrind after I bought it. I'm guessing that the PO (he's a mech. engineer and did his own valve adjustments) might have always had the valves adjusted too loose, causing pitting of the cams.

Needless to say, I'm real happy - but I don't know if I'd believe anyone telling me what I'm saying here (as I said, I didn't believe the PO).

I find this a bit uncanny. Aren't these motors expected to use, maybe a quart or so every 1 or 2 k miles?

[rdrr]

Sounds great - I guess you would like some reassurance that you have an excellent car !

I had a 1980 SC with 250k km on it that did not use a drop, just like yours. The engine had never been opened and it ran very very well. Didn't have any oil leaks either.

[DaddyGlenn]

My motor has about 80K on it and I see no oil usage either.

[HawgRyder]

I can lend you some of my oil usage if you like...LOL
Mine leaks...blows...and generally kills mosquitos in the nearby county.
So...don't complain.
And yes...it'd ready for the BIG rebuild.
Bob

[charleskieffner]

well think about this...........116k on 87 cab. fresh oil/filter leave phx. .....drive to fontana(fontucky) calif mtr. speedway. drive (5) PCA/SPEEDFEST time trials at mega warp WFO speed. ie. pinned the MOFO like its never been pinned ever in its LIFE!

drive(thats drive-not trailer) car back from fontucky to phx.

drive a few more weekends ripping up to payson/flagstaff/prescott.

after now 1779 miles, i have used 1/4 of a quart of oil!!!!!!

GO FIGURE!

from patrick racing..........porsche fabrik states" 1 qt. oil useage in 600-800 miles is NORMAL!"

thats worth sucking a few cold ones down, while admiring my ride!

dodged the dreaded valve guide thread for now!

[petrolblue83911]

My 83 with 155 on the clock can go 1k miles before it needs a quart, but it leaks about 3/4 of that onto my garage floor over the course of time... so I would guess that I am actually only using/burning about 1/2 quart every 1k miles.

[wolf]

not so unusual...i think someone collected data on oil consumption here on the board... livi?

[Wavey]

Just to reassure yourself, you might do a long, hot, high-speed run, and then check it. There is a SLIGHT possiblility that it is using some oil, and the level is staying the same because it's running rich and the excess fuel is getting past the rings, bringing the oil level back up. A long hard drive would burn off the excess fuel and bring the level down. Long shot, but it would answer that question.

BTW, my '88 with 83K uses about 1/2 qt between 5K changes of M1.

[DARISC]

I didn't stay at a Holiday Inn last night. But I do have a K&N filter

[jester911]

Mine really uses very little as well with 95k plus on it. The funny thing is it seemed to use less after I started tracking it on a regular basis.

I think that just means it was meant to be driven.

[skipdup]

My '83 RoW with ~130K uses no oil either.

[charleskieffner]

i now have a "CONE K & N " filter(saved 167 pounds over stock airbox assy) and it only consumed 1/4 of a quart of castrol gtx oil in 1779 miles of extreme heat driving.

put that in yer pipe and smoke it! LOL!

since its aircooled and the air aint cool in arizona..........i check it every time i take the car out. no leaks. none. NADA!

mantra..........leaks on airplanes bad................leaks on off road race cars-bikes-trucks....BAD................leaks on my p-car........

UN******* ACCEPTABLE!!!!!!!!

and yes at start up i get a lil smoke out of exhaust. big deal! when the motor pukes...............it pukes. what the hell!

"all things must pass."........G. HARRISON!

[DARISC]

Have cone K&N, no startup smoke.

[DanielDudley]

My 81 SC with 120 + uses no oil between changes. My 80 928 was using a quart every 400 miles, but has stopped using oil after becoming a daily driver. It had been sitting a few years prior to this. I drive it hard, after a full warmup.

They like to be driven.

[gunlover05]

I think there is something to being driven past 5K rpms every time you get these cars fully warmed up...i'm guessing it keeps rings/valves from gumming up....regular driving helps any car be more reliable too....

btw, my 85 carrera with 89K hasn't used hardly any oil that I can see in 2.5k miles (i've only had her 9 months though)....so i consider myself lucky.

[livi]

Originally posted by wolf
not so unusual...i think someone collected data on oil consumption here on the board... livi?

That was total mileage if I remember correctly.

I have the same situation. Change oil once a year, typically around 6-8k miles. Maybe lost 0.5 Liter at the most. I have also been contemplating the possibility that fuel/condensation replaces the burnt off oil. However I drive 90% highway and country roads and the car ALWAYS reaches full op temp. No drives under 30 minutes. As I understand, that would minimize the risk for the above.

But then what do I know about tech stuff..

[Lorenfb]

"When I bought the car the PO told me he did his own oil changes every 3k miles. I asked him how many quarts it used over that period. None, he said. Really, I said. Really! he said. I didn't believe him but that is it"

That's great!

"There is a SLIGHT possiblility that it is using some oil, and the level is staying the same because it's running rich and the excess fuel is getting past the rings, bringing the oil level back up. "

- Wavey -

It's the typical off-the-wall hyperbole, but again it's Wavey (an appropriate name).

Please avoid all technical threads and stick to your level of competence (or incompetence),
i.e. the Porsche accessories threads or how to make Porsche for sale signs.

[Wavey]

You may have never seen this happen in your vast experience, Loren, but I have. Perhaps someone with greater knowledge and experience than you (I know you don't think that's possible) will speak up.

Here's a search on the topic. Take a few minutes and read through it, you may learn something.

http://forums.pelicanparts.com/search.php?searchid=23358

Here's a thread that specifically addresses the problem of a rich condition causing fuel to get past the rings and to raise the oil level, which is exactly what I said could happen:

Fuel in oil.... followup

The search button is your friend Loren. You might try using it to avoid making a fool of yourself again.

[Wavey]

No response, Loren? Typical of your action when you're proven wrong.