Engine Oil Level

99hdtop · 99hdtop's Garage

I am new to this forum and also a new owner of a '85 911 coupe euro model. I was sitting at the drive thru at my bank and I noticed oil level gauge at lower level. Engine was not fully warmed up yet, got the car home and had to leave the house for a while. The Porsche was left at home. When I came back home I started the car and checked the oil level, nothing on dip stick at all. I realize that you should check oil with engine hot. Right now with engine off and stone cold there is nothing on the dipstick now. The car just came out of the shop (Rennsport here in Tulsa,OK) for transmission rebuild, cannot imagine them not topping off oil correctly. Should there be oil showing on dipstick with engine off, cold?

fintstone · fintstone's Garage

Car must be level, fully warmed up and the engine running.

99hdtop · 99hdtop's Garage

Should there be any oil showing on dipstick when cold, engine off?

theFONZ · 03-10-2013, 07:32 AM

Maybe, maybe not, but if it is good when hot and running that's what counts.

Joe Bob · Joe Bob's Garage

You've got 12 quarts....if you have oil pressure you have enough to run it to run it to temp to check oil level. Pressure gauge is in the dash. Likely to NOT have any oil on stick if it has sat for awhile.

Oil level gauge is worthless until you are at idle and level and warm...same as stick checking needs.

You could also call the shop and make sure it HAD oil, was checked, etc...I assume it was driven home?

Might want read up on the dry sump system. It will also smoke at start up....

Paulporsche · 03-10-2013, 08:17 AM

You probably won't get an answer on whether there should be any oil on a cold dipstick because:

1. It doesn't matter. As others have said, the only valid way to check is w/ the engine warmed up, idling for 1 minute, w/ the car on level ground, and

2. Most likely no one really knows, since it doesn't matter!

rusnak · 03-10-2013, 08:38 AM

When the engine is cold, the most important gauge is the OIL PRESSURE GAUGE.

Make sure the pressure shoots up on startup, and watch it a few seconds. Be sure as others have said to check the engine oil at least 180F or higher on level ground. The thermostat must be open, and you want to let the engine idle for a minute before checking the oil. Always check engine oil with the dipstick before adding oil. You want to keep the oil at the halfway mark, between Add and Full, at normal operating temperature.

99hdtop · 99hdtop's Garage

Thank You for the answers. Does the oil level gauge in the dash only read correctly with a hot engine also?

benzboy · benzboy's Garage

never go by the oil level on the dash!!! i have a 85 also. gauge will sometimes show low ,but on dipstick shows half to full most times.

99hdtop · 99hdtop's Garage

Joe Bob already answered that last question!!

mreid · 03-10-2013, 09:14 AM

You will typically see little to no oil on the dip when the car is cold, particularly if it sits on an angle or is parked with the left side lower. The oil in the tank slowly drains into the crank case. When you start it up, the oil pump removes the excess and as the engine warms up, equalizes the oil in the oiling system. I wouldn't be too worried about not seeing oil on the dip when not running, but check it as recommended before driving off and putting the engine under full load.

fintstone · fintstone's Garage

Actually, if your dash gauge is working properly and only observed when the car is warm and level, it is pretty accuarate. If it is not, you can repair or ignore it. Just verify its accuracy each time you check the dipstick and you will have an extra, recently verified warning of oil loss. I check my dipstick quite often, but check the gauge every single time I drive the car.

porschenut · 03-10-2013, 10:20 AM

Quote:

Originally Posted by fintstone

Actually, if your dash gauge is working properly and only observed when the car is warm and level, it is pretty accuarate. If it is not, you can repair or ignore it. Just verify its accuracy each time you check the dipstick and you will have an extra, recently verified warning of oil loss. I check my dipstick quite often, but check the gauge every single time I drive the car.

+1. The dipstick confirms my gauge's indication.

Joe Bob · Joe Bob's Garage

Like the clock....I ignore the oil gauge. If the oil level gauge didn't have something else combined with it, I would have given it the "liquid toss and float test"......

My clock hole now has a volt meter and a CHT. Useful information is a good thing.

Superfluous is annoying as is when it is frequently wrong, redundant and/or not working at all. Just my pet peeve on VDO gauges....

rusnak · 03-10-2013, 10:57 AM

I agree on the voltmeter. A real oversight by Porsche.

rgmrgm · 03-10-2013, 11:11 AM

Problem is you do not know where the oil is when the engine is cold. could be in the tank or in the engine and sump. Once the car is running the engine and sump oil should be returned to the tank allowing for a measurement. When hot, the oil expands to allow for a proper capacity reading. the oil level gauge should be used for a reference and one quart difference should cause a deviation from high to low, again when hot. A cold engine when running and filled to the proper capacity should cause some needle movement as it warms up. Some people recommend running the engine a quart low. probably OK during cold weather but not when the outside temp is hot. People call the 911 an air cooled engine but in fact it is cooled by oil and air and proper oil quantity is essential.

Joe Bob · Joe Bob's Garage

Quote:

Originally Posted by rgmrgm

Problem is you do not know where the oil is when the engine is cold. could be in the tank or in the engine and sump. Once the car is running the engine and sump oil should be returned to the tank allowing for a measurement. When hot, the oil expands to allow for a proper capacity reading. the oil level gauge should be used for a reference and one quart difference should cause a deviation from high to low, again when hot. A cold engine when running and filled to the proper capacity should cause some needle movement as it warms up. Some people recommend running the engine a quart low. probably OK during cold weather but not when the outside temp is hot. People call the 911 an air cooled engine but in fact it is cooled by oil and air and proper oil quantity is essential.

No you don't, hence the need for an oil pressure read and listening for clacking valves after start up.....dry sump motors don't have an ability to tell you about engine oil capacity when cold or at rest.

You could drain the oil, measure it, put it back in......but that's not optimal.

dshepp806 · dshepp806's Garage

All good suggestions.....eventually (after changing out my oil level sending unit) I was able to get the gauge to respond to the stick (in the normal parameters to check the stick, BTW, although I do allow for my thermostat to open on the front oil cooler lines, ensuring they are warm, as well).

Kinda' neat, for entertainment purposes only,..I (still) would never trust my gauge over the stick measurement under any circumstances......

The stick is the reference.....period.

You're cold oil level question looks to have been answered.

Now,..back to +180 degrees F..........................

Best!

Doyle

DRACO A5OG · DRACO A5OG's Garage

if it bothers you I posted a fix to match the level to both oslu and gauge, search my name, it is length but should give you a guide.

bottomline, dipstick is the best guide after she is hot and idling on level ground, like at a gas station while filling up, just wait a minute to allow the oil in the tank to settle down. Heck even if you are low, don't worry about it, our babies have plenty of oil until you get her home to top her off.

I just sent all my gauges to NHS, all needed calibration.

jim