H2NO

I added a quart of oil about 600 miles ago to about the 3/4 mark on the dipstick. Now, its showing a little over half. Should I wait or am I getting dangerously low? Is 600 miles per quart evidence of valve guide wear or is it within the acceptable range? The car never smokes and the engine runs smooth as silk. Its a 1989 3.2. Thanks. By the way, I have searched this issue exhaustively, but I'm hoping there are some more pearls of wisdom out there as this is my only real fear concerning this wonderful automobile.

racer

I would guess that 600 miles is getting closer to the higher side of the consumption spectrum. Also depends on how the car is being driven (low stress street or high temp, high stress track use).

theiceman

1/2 between min and max is where it should be anyway , don't add till it gets low ( er )

RacingBeat

going thru the same thing.....been trying to get the feel for my 84 3.2 over the last 9 mos.......a few of the year's hottest in there. looking like a qt every 900 miles, i'm staying between 3/4 and 1/4 on the stick....no drips on the floor but it's something i'm watching closely. my oil level gauge falls off noticeably as it gets on the low end, which seems to be trustworthy...?

H2NO

Racing Beat, when you're at 1/4 and put a quart in, where does it go on the stick? I'm having trouble equating oil amount with oil level. For instance, how can one quart equal almost 1/4 on the stick when 1/4 of all the oil in the engine should equal 3 quarts? Or am I missing something?

theiceman

That is actually pretty funny, I hope you don't mind. Racing beat means that if the distance between min and max on the stick represented "1" , than half way between min and max would be 1/2 . if you go down in oil 1/2 way again you are at 1/4 of the dipstick marks. The actual oil between min and max I believe i about 2 qts if I a not mistaken. I have a 930 dipstick so it is a little less, I would say 1.5 quarts. So when he is betwen 1/4 qnd 3/4 he is varying about the centre point of the dipstick by adding a quart...

ice

PS did I totally confuse you now ???

H2NO

Iceman - no offense taken. I think you answered my question, but I'll state it more clearly, "how much oil is the dipstick actually measuring?" Is it only measuring the top two quarts? That would make more sense. If that were the case, if there are 14 quarts total, and the car had only 12 quarts left, it would be at min. So, one would not add a quart until the dipstick reads below 1/2 (less than 13 quarts).

Droops83

The distance between the min and max marks on the dipstick is 1.75 liters, which is 1 and 2/3 quarts if u want to be exact. Its says so on the sticker in the engine compartment, but i guess if yours is missing you wouldn't know that . . . .

and btw the 911 usually takes 10-11 quarts, unless it has an aftermarket front mount oil cooler or something, I don't know where you're getting 12 and 14 quarts from. If the stick shows halfway between min and max w/ the car warmed up, you probably have about 10 in there. I don't understand the confusion here. . . .

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Chris A.

Bretech

Maybe he's checking the oil with the car shut off.

theiceman

btdt50 you are right, you are only looking at the TOP 2 quarts or so , and the comments are made in reference to these top 2 quarts , I think chris said it is 1.75 but you get the drift.

Edward

If I may state the obvious, remember that your tank + lines contain approx 12 qts of oil. Down a full quart or more means nothing to your engine, really. Would I run it below the dipstick normally? Of course, not. But running at or near the bottom of the dipstick is pretty common among those who track their cars simply because the elevated temps (under track conditions) results in more oil expansion and you don't want overflow!! While the overflow is not my point here, what I'm driving at is that even under track duress the car is perfectly happy with the oil level "low" ...which of course, it is no where near low of oil. So in my very long-winded reply, I'd add oil when you get at or near the bottom of the dipstick. Hope this helps.

Edward

H2NO

Thanks for all the answers. The reason I may sound naive on this subject is. . . that I am. This is my first air cooled Porsche and therefore the first time I ever really cared about oil. Although there is plenty of information on this subject, nothing compares to the knowledge of many who have been living it.

Jay Gratton

Wow, you guys keep talking about your oil comsuption and my '85 911 with 165K only goes through a quarter of a qt. a season. I know people who go through a qt. with the same mileage your talking about. I personally wouldn't worry and make any big repairs yet. Just keep watching it and make sure it doesn't go below the bottom line.

H2NO

I wasn't planning on doing any repairs yet. Armed with my new found knowledge, I think my oil consumption is fine. How many miles do you drive in a season? A quarter of a quart per season doesn't mean much in term of oil consumption.

Chuck Jones

Edward makes a lot of sense...when the oil level gets below 1/4 or actually even a little lower, just add about a bit at a time to bring it back up to the half way mark on the dipstick...which usually only amounts to about a third of a quart. I usually end up adding about a total of 1/2 quart per 1000 miles.

Happy motoring....Chuck