Yamaha64

Hi I just purchased a 1990 911 C4 and I LOVE it. I changed the oil and added a total of 9.5 liters of oil and it is just showing on the end of the dipstick. the oil gauge is not moving. So I added another 2 liters to total 11.5. Now the oil level on the dipstick is at the top mark and the oil gauge is at the top. But I read that this is too much oil. Can anyone tell me if it is too much oil or is this correct? Thank You.

Vandit

You are likely overfilled. In my experience, once the car is up to normal street operating temp, I try to get the oil level to just the bottom of the dipstick. If you continue to fill it like you did, then next time you drive the car in a more purposeful (racing) manner, your oil level will be off the scale.

Basically, the difference in oil level registered between street operating temp and racing around operating temp is substantial.

Yamaha64

Is your oil level at the lower mark on the dipstick or below?

greg1990964

Get your hands covered in oil and let a bit out of drain plug in front of rear wheel. Then get car warm and add as needed by watching the gauge. I like it about 3/4 up on gauge. Got to keep adding a little as you stare at the gauge and check dip stick. Fun!

JasonAndreas

You have overfilled by 2 liters. When you are pouring in oil (after you've drained it, fill with 7 quarts and then start the engine running), as soon as you see even the slightest movement on the gauge. STOP. You are done (it will be about 9.5 quarts in total). If you start playing with the level trying to get it at the halfway point at some slightly random temperature you will have problems with oil venting into your ISV and intake manifold the next time the engine really comes up to temperature.

Richard Curtis

All good advice but I wouldn't suggest trying to drain oil via the drain plug. Instead, buy a simple turkey baster and suck it out the oil filler tube. I've learned that the oil level gauge is not dependable UNLESS the oil temp is really hot, especially when the ambient temps are cold. Also only measure oil level when the car is one a level surface, idling for at least 30 seconds. You should know that draining the oil tank doesn't drain ALL the oil; there is considerable oil in the oil cooler and tubes (usually around 2+ quarts). When you drained it, did you also drain the sump?