For what its worth, with my car up to temperature, I check the dip stick and if its marking low I only put in a 1/2 quart at a time and continue to check it until its marking safe. I have over filled in the past and learned my lesson. Fortunately for me my gauge works fine too.

On a side note C2S, when you are done with the oil issue you should grab some Windex and get all that grit off the gauges in the picture. LOL Just messing with you man.

 

My Oil Gauge is spot on either 1/2 way or 3/4 when properly filled. Car must be up to temp though for the reading to be accurate and on level ground. Being in the red and your car up to temp...there is something clearly wrong with your gauge, sending unit etc.....

 

No, not in this case. But cgfen says that most read consistently high or consistently low, so in at least some of these the level can be judged.

Mine reads OK for 100-200 miles after oil change. After that it seems to be off the reservation on the low side, just like OP's. Occasionally it would read higher. Adding oil doesn't make a difference in readings. So it's random, as far as I'm concerned. I have stopped paying attention to it at least a dozen years ago.

 

I'm just spit-balling here but most likely because the oil LEVEL gauge does not measure temperature? Whether the temp or level gauges work or are reliable, is another matter altogether.

nile13, I get your point, but I couldnt resist the level/temp relationship...; )

Theoretically, yes. Hectically, not so much...

If its inconsistent, its most certainly unreliable.

Snowbird, the word "calibrated" means that the gauge is set to some known "standard" (which is the point cgfen was leading to); however, this is clearly not the case in this respect..

 

It doesn't. In most cases with 993s it doesn't measure level either.

 

Everyone's is calibrated differently. It sounds like your gauge has been adjusted to show at a certain range (1/2 to 3/4).

When my oil temp is hot (pointing to 9 o'clock), my oil level gauge points at the top of the red bar. That's my calibration to the dipstick showing the oil level at about 1/3-1/2 up the marked area. If the gauge shows lower, I check the dipstick and add a bit more oil if necessary.

When the temp is lower (like what the OP is showing), my oil level gauge is deep in the red range (when stopped on level ground).

 

You obviously have a "rogue" dipstick. Need to keep your dipstick in check!

 

Replace both filters and drain oil tank and engine case
put in 8 to 9 quarts, run engine until nice and hot. Measure oil with engine running add oil 4 oz. at a time until oil reads at bottom of oil fill range on dip stick. If using gauge fill hot until gauge floats to middle of range. Oil is hot when the oil pressure settles down below 3 bar. Over filling is not good. It seems both the dip stick and the gauge vary in absolute read out from car to car so think less is more when initially filling as you can always add more later as you get to know your car. If you end up putting more than 10 quarts in you are over filling it.

 

I get that. The fact is, if your gauge reads consistently low then you can't rely on it to show you when your oil level is low. Hence the OP's oil level gauge is unreliable as per my post.

I find cgfen's characterization of this statement as a "typical internet alternative fact" inaccurate and frankly insulting. However the offense is mitigated somewhat by the fact that he contradicted himself within the same post.

 

Not sure anyone should attempt to argue the validity of the Donster's point!

 

They are available right now for about $100 retail. Have you ever replaced an oil level sender? In my direct experience it adds just minutes (not hours) of labor to an oil change.

Regardless, Gbos1 is right - use the dipstick until you know the calibration of your gauge. Mine (and many other 993s I've checked) would read in the red, with a perfectly filled tank of oil, so I adjusted it per MikeJ's comments I could dig up if anyone is interested.

Post adjustment, my oil level gauge is consistent and accurate. At a given temperature, volume of oil, and on level ground, it will read the same on the gauge every time. I've found controlling those 3 variables to be tough in the real world...especially temperature. Without an oil cooler override fan, oil temperature on a stock 993 can move around a lot making the gauge seem inconsistent.

It's pretty simple mechanism once you look at it.

 

In my 86' Carrera the oil tank gauge float arm was easy to get to and could be bent up or down if one wanted to adjust the dipstick to gauge variance. Can this be done on a 993?

https://www.google.com/search?q=pors...vY7TS13KDNM%3A

 

Yep - that's the adjustment Mike has mentioned many times. You just add a slight bend to the arm. It's very easy.

 

The thing with mine is, as I've mentioned, that it works differently for the short time after oil change than it does afterwards. I'm not sure why.

 

So back in August of last year I was quoted by my local Porsche Dealer a new Oil Sending Unit and Labor for $895. My SA whom I know very well said it was a labor intensive job. I thought my gauge wasn't working properly but in reality I had just taken delivery and didn't realize you had to really get it up to operating Temp for it to operate properly. this was the case with mine and is OK.