Correct Oil Gauge Reading

[Izzy]

Got a basic question. What is the proper way to measure the oil level on a 1999 996? The manual has two methods, the instrument panel and the dip stick. For the instrument panel, once you turn the key and wait for the count down, the display shows the level.

The dipstick mentions the car at operating temp, then turn off and wait 10 minutes or so.

When my car is cold (like in the morning), the instrument panel shows only one bar on the bottom, like if it was low. After running at temp, and letting it drain for 30 minutes, both the dipstick and the instrument show perfect fill.

I am assuming to ignore the cold temp instrument, and go with the warm engine measure. The reason this just came up is that I only noticed the cold engine low oil level (instrument) after a dealer oil change (before I found this Forum)

Of course, the car on a flat surface for all measurements.

Thank you for your collective wisdom!

[gavinmead]

I have also been wondering about this. I'm of the mind that the dipstick is the way to go, but then again, I work in IT so I mistrust computers by default. :P

[1999Porsche911]

Get your reading from the dipstick when the car has been sitting level for 15 minutes or more. Then look at the electronic gauge and see where the level is indicated. The gauge is extremely accurate.

It does not matter whether the engine is warm or not, but is IS necessary that you let the car sit level for 15 minutes or more for an accurate reading. Just look at the gauge before you start the car in the morning. I haven't used the dipstick in 5 years. Long before you ever get to an oil level that is dangerously low, you will be alerted to that by you oil pressue gauge reading low. Get to know the habits of this gauge also and you won't have any problems.

Edited May 10, 2005 by 1999Porsche911

[Coaster]

Long before you ever get to an oil level that is dangerously low, you will be alerted to that by you oil pressue gauge reading low.  Get to know the habits of this gauge also and you won't have any problems.

<{POST_SNAPBACK}>

Good advice -- I wish I could heed it but I don't trust my oil pressure gauge.

Per the manual "With a warmed-up engine and at a speed of 5000 rpm, the engine oil pressure should be approx. 3.5 bar." Mine has always read 4.75 bar at 5000 rpm, even after the dealer replaced the oil pressure sender.

[1999Porsche911]

Long before you ever get to an oil level that is dangerously low, you will be alerted to that by you oil pressue gauge reading low.  Get to know the habits of this gauge also and you won't have any problems.

<{POST_SNAPBACK}>

Good advice -- I wish I could heed it but I don't trust my oil pressure gauge.

Per the manual "With a warmed-up engine and at a speed of 5000 rpm, the engine oil pressure should be approx. 3.5 bar." Mine has always read 4.75 bar at 5000 rpm, even after the dealer replaced the oil pressure sender.

<{POST_SNAPBACK}>

Don't follow the manual. Find out what the normal oil pressure readings are when it is known that the oil level is correct. The pressure should be close to the following.

Idle and above when the car is cold - 5 bar

Fully warmed idle 2 bar

Fully warmed above 3000 rpm - 4.5 bar or higher. (probably 5 bar)

If you only read 3.5 bar as the manual indicates at 5,000 rpm, you have a problem.

Edited May 10, 2005 by 1999Porsche911

[Coaster]

Thanks for the suggestion -- I guess I'm not the only one whose oil pressure gauge readings differ from the manual. Maybe it's a typo in the manual? That's kinda funny in a way because the dealer didn't even question the need to replace my oil pressure sender.