deuce1

So when I bought my 993 Turbo the oil was done before I received, lately the car has been smoking on startups.... I always check the dipstick every few days and the oil always seems to show at the top of the spirals.

I thought maybe the oil was too high so I will try to drain about a half quart to a quart and see where that leaves me on the dipstick as everyone here seems to say about half way up the spirals. (BTW the official Porsche Oil Filters are on this car)

So I loosened the oil plug on the bottom of the motor next to the heater flapper just enough so oil would drool out. only about 3/4 to a quart came out before it stopped flowing anymore. I tightened the plug back up and checked the dipstick and it is bone dry.

My question is was this the wrong place to drain oil from? will it damage the engine if I try and start it to cycle the oil through the entire car, when it is dry at the bottom of the motor??

Or is the oil pump at the bottom and would only be sucking air and not pumping oil in the system since I drained about a quart out?

Sorry for the long winded post, but would appreciate your expert advice asap? Thank you in advance

Basal Skull

Well, that's the right plug to drain oil from the engine. The drain plug for the tank is in front if the passenger rear wheel. Usually to only drain a small amount, most just drain from the turbo reservoir. If you're asking about the safety of starting your car because your dipstick is not registering after only draining 3/4 quart, it implies that you are not checking your car properly... You need to have your engine idling and warm to check your oil on the dipstick. Without the engine running, it will always not register on the dipstick! Our cars have lots of oil, if you only drained 3/4 quart, you should be safe to start.
Oh yeah, welcome to the forum!

ca993twin

To amplify a bit on Basal's post, the car must be HOT, level, and at idle speed to measure the oil, either on the gauge or the dipstick.

deuce1

Thanks for the responses guys, I always check the oil when its hot after a drive running while parked flat in my garage.

When I let the oil out it was still hot from just driving the car, so technically when I checked it after it was still hot but not running.

My question I guess is the oil pump located in the area of the motor where I let the oil out, thus not being able to pump oil to prime the system, or is it located somewhere else and I should just start the car and let it run and eventually the oil will fill back up in the bottom of the motor?

Or should I pour the oil back in the motor and try and drain again from somewhere else like the turbo reservoir?

Thanks again!

Felix

You must check the oil level with the engine running at idle with the oil hot. Checking with the engine off is of little to no use. Checking with the oil cold is also wrong because oil expands slightly as it heats up.

The car has what is called a dry sump so the vast majority of the oil is in the tank into which the dipstick goes. You'll never get much out of the sump.

Quadcammer

You are thinking about this incorrectly or are picturing it from a wet sump perspective.

The oil pump is located in the vicinity of the drain plug. But, there are 2 or more stages to the pump, and there is the external oil reservoir.

Heres how it goes.

The oil tank holds the majority of the oil and then the "pump" side of the oil pump takes that oil and pumps it through the motor. The oil then drains back down into the case where the "scavenge" side of the pump sucks all the oil from the case and sends it back to the reservoir.

The idea behind this is that there will always be a full stream of oil going to the pump and there will be no oil sloshing around the case to create windage.


The dipstick reads the oil only in the reservoir and after sitting for a while, some oil can actually leak through the gears of the pump (i believe) to end up in the crankcase (the 3/4 of a quart you saw). Hence why the car needs to be running.

deuce1

Thank you all for your expert advice on this, this is my first 993 Turbo and have only had it for about a month now and I am learning a lot about it quickly.

So I am going to head down to my garage in about an hour to start the car and let it run, as you guys have suggested it should be ok to do so and the oil will eventually pump back through the system and into the bottom of the engine where I extracted oil from the drain plug.

Quadcammer

not quite.

the oil comes from the external tank, so there is no "eventual". Furthermore, in a perfect world, there would be no oil sitting in the "bottom of the engine where you drained it"

Oil there is bad, hence the pump sucks it out of there while the car is running.

TT Surgeon

Good info