jsabatini

I know engine warm with car still idling.

Was reading the 101 projects today and it said when the needle is in the middle the car is full. After an oil change I took the car out to warm it up and when I got the car back in the garage the oil level gauge was around 3/4 but the oil level on the dipstick was a little over 1/2 between the two marks.

theiceman

There a couple of variations of sender and a couple of dipsticks. I am sure you are going to get a ton of " don't use the gage. only trust the dipstick " which is true, but when I replaced my sender with a newer style in my 78 and replaced the dipstick with the matching one ( a 930 p/n i think ) The gage is VERY accurate. full is at the top mark add is at the red .. and I run it at half way between.

Steve Weiner-Rennsport Systems

All I can offer is that the vast majority of overfilled 911 engines I've seen were from owners who used the gauge to determine oil level.

Some of them had intake manifolds full of oil, too.

Caveat Emptor on anything but the dipstick.

dshepp806

without question: +1.

tone40

Or, how much to add when the oil level is at the lower mark?

JABSEA

Volume between marks is 1.85 qts.

theiceman

when my gage reads on the red I as stated i am on the "add" mark or lower mark. 2 litres will put me on the full Mark and the gage is at the top tick. I must admit however I have never actually gone down to the add Mark . my car uses about .5litre in about 5000km and then i change it so I never actually get low enough to add.

Interesting to note that the newer updated dipstick i got with the updated sender ( basically avesion from a later car ) showed the marks LOWER on the di[pstick than my original 78 dipstick ... i guess Porsche echoed Steves sentiments and revised the dipstick to prevent overfilling and spilling into the intake on hard cornering ?

things that make you go hmmm......

Marty916

According to the book, there is about 1-2 quarts between the low and high marks on the dipstick. Seems like a rather large range of volume to me(perhaps related to model/year and/or amount you were able to drain from the system during an oil change?) so it's best to sneak up on it by adding half a quart at a time until reaching the desired level. As mentioned before, too much oil may over-pressure the crankcase and end up blowing into your air box or worse, damaging seals and stressing the rings.

3.2SLANTNOSE

I am sort of like Marty, but when I change the oil, I go ahead a dump in 11 quarts, then use what ever amount is needed out of the 12th quart. My gauge is about as accurate as the rest, but I depend on the stick to make sure all is well. My car has the front center mounted cooler also, so when I change the oil, I buy a case, because it will take just about all, for the refill.