Suddenly getting low oil level???

[pauls81sc]

Hi all,

Something has changed and I'm suddently getting low oil level readings at startup.

Here's my history: Since I purchased the car, the oil level has always jumped to near the top when I move to the accessory position on the ignition switch. And it has always stayed pretty well near the top or about at the mid-point while driving.

About a month ago the oil level gauge was reading low (just above the red) when I first turned it on. After warming up a bit it comes up to middle of the gauge or higher. Why the sudden change?

Now, I completed an oil change, including a couple oil lines, over the weekend and topped it off again. First time I turned it on, the level jumped right to the top. Ran it a bit and everything looked great (temp, pressure, level all good). After letting it sit overnight I got the same low reading at startup. The dipstick is reading just a hair over max so I'm going to let some out before I start it up again.

Now I've already done a search on the BBS and it seems that the concensus about the dash gauge is that it is notoriously unreliable. This is really hard for me to accept since the oil level is well lets say "kind of important" in an air-cooled engine and since I was getting such good readings just a few weeks ago.

Has anyone else suddently developed this condition, and if so what corrected it? Is there a way to verify the sender is working correctly? Any other comments on oil levels / dip sticks / gauges are greatly appreciated.

[GB83SC]

Paul,
don't even look at that sucker. The only way to know for sure what your oil level is at, is the dipstick at temps above 190.
My car : when I turn it on it stays at the bottom until I reach operating temps, then it moves up.
They are all different some work great and some are crap.

[Wil Ferch]

The gauge is not notoriously unreliable. What it is....is that it's notoriously precise in following each and every fluctuation of *actual* level. It is only meant to be read when all three of these are in proper order:
- oil at about 190 degF
- car is on level ground, and
- idling..about 880 rpm, say.

Even a fast idle like 1200-1500 rpm will likely get you down into the red zone. It is normal to be into the red zone while driving too.

As to the change, look to spooky electrics like flakey grounds or even a bad gauge or sender. Once it's operating, it's incredibly accurate to what it's actually *seeing*....


---Wil Ferch

[Jack Olsen]

All of this is good advice -- you were heading for an overfilling situation, which is a nightmare to clean up.

Drive the car for 20 minutes before you check it, then park on a level surface, and check the dipstick with the motor idling. Fill it up to the midway point between the two marks on the dipstick.

[pauls81sc]

Okay...First off I want to thank each of you for the replies. This BBS is quickly becoming the best tool at my disposal for working on the Porsche. Muchos muchos gracias.

Everything you've described about warming it up, parking on a level surface, being at idle is exactly what I do to check the level with the dipstick.

Originally posted by JackOlsen
-- you were heading for an overfilling situation, which is a nightmare to clean up.

Jack.....could you elaborate on that, please?

Originally posted by Wil Ferch
It is normal to be in the red zone while driving too.

Wil...in the year or so I've owned this car I cant remember it ever going into the red zone even with the low readings I am getting now. I'm so paranoid about hurting her that I think if it did drop into the red and stay there that I'd shut her down. Especially since that doesnt seem to be normal for my car.

Any more opinions out there about what's normal or not?

Thanks again to all of you for the assistance.

[GB83SC]

Paul. Lets try this again.
I have a 83SC-
When I start it its in the red zone.
When I drive it its in the red zone at any temp.
When I stop and its hot the needle shows the oil level.
That is the way most of them work.
Check the oil by the dipstick.

Muchas gracias Pelicanito!

[Jack Olsen]

Your car has at least 12 quarts of oil in it. It's designed to be able to run on 4 quarts, so long as RPMs are below 4000. So you don't have to be as concerned about being a quart low as you might be with a 5-quart-capacity domestic car.

The problem with overfilling is that the oil can get up into the airbox, and smoke like crazy until you take it all apart to clean it out. It's a typical situation for new 911 owners, who bring the oil level up to the top mark on the dipstick with the engine cold, or even turned off. When things warm up, oil gets everywhere.

The interior gauge is based on a float inside the oil tank. Under heavy acceleration, the needle will typically drop into the red, pegging to the bottom end of the scale. This is not a problem.

[Wil Ferch]

Jack and others are correct.
As another point of consideration, people indeed do fill to the "full" mark, and when the oil gets even hotter than usual, it expands and leads through various hoses to the car's intake tract. Later, when the poor guy checks the oil level again, his car has "apparent" high oil consumption. So what does he do? Fills it to the "full" mark...and the sequence starts all over again. Then we get reports of "Jeez.. my car uses 1.5 quarts of oil every 400 miles". And the inevetable engine and valve guide rebuilding questions.
Do yourself a favor. Fill to the "mid" mark , or even just a smidge under...and keep on checking on this basis. You'll probably find that the oil consumption isn't as bad as you think.
One last point... 190 degF is just under the 9 o'clock position for most guages. IF you're not careful, you might find that the level takes a leap in reading at about that point when oil gets diverted to the front oil cooler.....if you have one. Therefore, don't let it get too warm when you check the oil level.
-- Wil Ferch

[ChrisBennet]

Keep in mind that the gauge and the dipstick only measure the very top of the oil level - sort of like sticking your finger in the top of a bottle to check the level.
-Chris

[pauls81sc]

Okay...I'm starting to feel better now.

Knowing that the oil level is not representative of the entire reservoir, it in fact represents just the top, certainly helps my peace of mind and also explains why Wil doesn't mind running his in the red. I suppose the real indicator than is the oil pressure. As long as that is normal than everythings okay.

I know there is plenty of oil in it cause I just filled it. (maybe even overfilled it a bit) I'll let some out and see how it goes.

Wil, Jack, Chris, and GB83SC,
(*sniffle*) (Wiping a tear) I LOVE YOU GUYS (*sob* *sob* *sob*)
Paul

[GB83SC]

OK. Group HUG!!

[Doug Zielke]

Originally posted by JackOlsen
The interior gauge is based on a float inside the oil tank. Under heavy acceleration, the needle will typically drop into the red, pegging to the bottom end of the scale. This is not a problem.

No it's not.
But the needle does not drop due to 'heavy acceleration'.
It drops because oil is leaving the tank faster than the scavenge side of the oil pump can get it back to the tank.
This occurs as revs increase much beyond idle.

[Wil Ferch]

Dry sumps...and Porsche dry sumps in particular.. are peculiar creatures so don't feel bad about asking questions or getting clarifications.
Not only is "Wil" comfortable with actually running the car in the red..it pretty much says so in the various owner's manuals and workshop manuals....that the gauge gives an accurate rendition of level only when the "three conditions" are met. The scavange and pressure sides of the oil pump are different sizes, and as soon as revs pick up and you're moving...you will likely always be in the red zone. No concern..the gauge shouldn't be heeded under these conditions, although it does make for some entertainment watching it blip up and down as you drive, come to a stop, etc....
---- Wil Ferch