OldGuy

I think all the guages are different. on my TT after an oil chage on level ground and warmed up and dipstick almost to full my guage read just off the red mark. So I used it only as a rough estimate. The dipstick does not lie.....

kkim

Darin,

That depends on how many you take out. I've been reading lately on how much more oil comes out if you wait an hour or two. I don't wait that long.

I put in 8 qts after a oil and 2 filter change, warm up the car, check for leaks, then top off (between 1/2 and 3/4) using the dipstick. Usually ends up about 10-11 qts.

STLPCA

That's too high. Even in stop/go traffic on a 100 deg day my 993 doesn't get that hot. Constant high rpm track temps may get it to 200 +/- deg in the heat of summer. Is your engine tray off? Is the low speed oil cooler fan resistor working? A "no" to either may explain your higher heat levels.

Flying Finn

Actually it is for 993 (as well as for 964). And between the marks is about one quart.

If you fill it all the way to the top, if/when the engine gets really hot (i.e. at track), oil expands and you might end up with too much oil and it overflows.

Keeping the oil level in the middle as the manual says is better and you certainly have enough oil if it's in the middle since there are total of about 12 quarts in there.

BTW, when you fill 12 quarts, that's a lot imo since the capacity is about 12 quarts and there's always some oil left in the cooler & lines from thermostat to the cooler.
Since you're only checking with the gauge are you sure your gauge is not pegged all the way to the top after the change?

coltj

Jason, Monique and Dan,

Thanks again for your comments;

to everyone else, sorry for high-jacking the thread.

I suspect my data logger may be mis-calibrated, if that's possible. My temp gage indicates normal temperatures in city/highway driving conditions. That is the needle gage never goes above the 8:00 position(3rd line from the bottom, including the 2 lines close together). And I do see evidence that the thermostat is opening as the needle position drops. In addition, I just picked up the car from EPE after an oil change and Jerry reported everything is fine 800 miles after rebuild.

rainmn

Timely thread, since I just checked my oil / calibrated my gauge right now. I've put about 1,500 miles on the car since I got it (Had an oil change at time of purchase) and according to the gauge, it looked to me like I may have burned a 1/2 quart or so. That turned out to be accurate.
A few observations / thoughts:
- The dipstick design in our cars sucks...period. I'm glad we have the gauge to "Double check" against, since no matter how many times I try and read the dipstick, I'm never positive I'm seeing where the oil level really is.
- My gauge and dipstick (If I'm reading it right) are dead on with each other. If the gauge is barely leaving the red, the dipstick is barely in the twisties. Same for the upper end.

One question - what is the ideal position on the temp gauge to be checking your oil at? Is it around the 9:00 position?

cabrio993

How did you calibrated your gauge? Is there a calibration at the gauge? Or the sending unit?

rainmn

Not as scientific as it may have sounded....
All I meant was comparing gauge readings to dipstick readings. I did this before and after adding the 1/2 quart or so that I was down.

Baggerdude

<<A few observations / thoughts:
- The dipstick design in our cars sucks...period. I'm glad we have the gauge to "Double check" against, since no matter how many times I try and read the dipstick, I'm never positive I'm seeing where the oil level really is.>>


Ray, I gotta agree with ya. When I pulled out this (is it 4 feet long?!) dipstick and saw this twisted deal with some lower and upper demarcations, I was scratchin' my head.

What I did was wipe it COMPLETELY clean with a lint-free cloth ( I guess it was lint-free... ), then I reinserted it.... pulled it out... wiped..... and did this until I was SURE I was getting a good reading.

I must admit.... I've owned many vehicles that had EZr dipsticks to read, including a $1200 (US) lawn tractor! What's up with this..?

AND.... what German car maker tosses in an oil gauge in an air cooled car that doesn't work PERFECTLY? How hard is it to have a gauge that reads oil level in a car that has a 35 year or so history with prices as much as my home? I'm amazed.

Anyway, I think that adding oil to the car to get the level at mid point on "the stick" is the way to go....providing it at "operating temperature". Also, when doing this check the gauge and see if it ...sorta.... compares with the dip stick reading. That's kewl....

BTW... thanx everybody for the posts. This is a place where opinion, experience and tech all come together. Albeit somewhat sarcastic.

STLPCA

FWIW, I lightly scored the twisted portion of my car's dipstick w/a Dremel which made it somewhat easier to read.

993inNC

Monique, I would have to say that you (and Steve) are very correct. If you don't use the car much, use the stick. On the other hand if you use the car as I posted earlier, you get to know how, when and why the gauge moves. Besides even if you don't use the car, if the gauge doesn't move, that should be one of the first indications something may be wrong....no? And someone here commnted about letting th car warm up for a minute.....I never just start the car to check the oil, my understanding is that the car is supposed to be up to normal operating temps to get an accurate reading otherwise you haven't cycled thru the coolers yet.

Finn, my manual says (I believe 12.4 US quarts). If you do a "complete" change, which includes draining the crank case, both filters, the oil feed line and actually have the car on a slight bias to the rear when jacked up to drain the lines to the coolers......I got 12 quarts (minus a small spill factor towards the end) in and have never had blow by, leaking, smoking or anything. I was doing 150 mph in it for a good while and nada! And no my gauge doesn't just peg when full, it works its way up at idle and down as I accelerate (down to red when WOT and about mid way during regular speed/load).

Flying Finn

Chris,

I though it's something like that (12.4 quarts), thanks for confirming.

Oil feed line? Do you mean just the drain bolt where thermostat is or do you actually loosen the oil line from the thermostat and drain oil from the cooler & lines also?
If yes, then obviously you'll get almost all of the oil out, I just do it in regular way from oil tank & crankcase (I do change the filters of course) and therefore don't get the oil from the cooler.

I've been thinking of doing the above and loosening the line because it would be better to get all the oil out but haven't done it yet...

In any case, you're not having any problems since surely it should've been overflowing already with driving you're doing up there so no problems with that!

Luis A.

The oil float is nothing more than a resistive element and the gauge a simple voltmeter. It moves up and down about 3 - 3 1/2 inches. I've confirmed a linear correlation between the gauge and the float position in my car. It can't be that innacurate, I believe oil temperature is the culprit variable most of the time.


I agree with Jason that temperature is critical or the reading varies widely. I always read the level once the oil has warmed up to the point that oil cooler fan kicks in. I've visually calibrated my gauge and 1/2 full corresponds to 3/4 full on the dipstick. I'm sure its designed that way to render a conservative reading.

993inNC

Finn, no the oil line just below the engine filter, held in with single bolt to the bottom of the case....think it comes from the tank? can't recall off the top of my head. But I keep the front end up higher than the rear in the hopes that the oil drains back from up front. Question begs....how much oil is trapped in the coolers if the thermo is closed. Is there a drain by-pass or does it remain full? Any idea of the capacity of each cooler?

DarrylH

OK. Get car HOT. Oil-cooler-fan-on HOT. Idle one minute, minimum. Level ground. Not moving.

Read gauge. Read dipstick. Should be close correlation. Most problems arise because - not HOT enough.

Dipstick hardly shows sometimes. PITA. Can't be helped. Gauge OK? OK. Dipstick OK? OK. Gauge questionable, dipstick OK? OK. Gauge OK, dipstick questionable? Check dipstick again. Don't overfill. Too much is bad. I'd say a false high reading on the gauge would be very rare. Schmeared dipstick is very common.

HOT. Level. Idle one minute minimum. Stationary. You're golden.

Until the car is HOT - pretend the car doesn't have a level gauge. Watch the oil pressure and oil temp instead. Takes your mind off the level gauge!