AKTUNG

Synthetic oil usually leaves behind a film . I had a customer once who changed the oul in his bike and did not tighten down the drain plug. Lost all oil and rode for near 20 miles before realizing he had no oil. No damage done.

luckyJ

wow, that is interesting...can you please try that on your next oil change...I know 993s are durable, but if you can pull it off...that would be just awesome....thanks

Mike J

On a NA car, I find its almost exactly 10 litres assuming you change both filters, drain the tank, sump and remove the main feed line to the pump.

Instead of starting the engine, you can crank it over without ignition or fuel by removing the DME relay. Not sure how that would help anyways, the lines from the thermostat to the front cooler will still remain full of oil if the system has cooled down any since the thermostat will be closed. That is where the bulk of the oil will be, and the bit left in the engine will not drain no matter how much you crank since its caught up in the recesses of the internals. Even if the thermostat is open, the oil goes though a large rise/fall in the front wheel well that will tend to not allow the front cooler to be drained.

Given the large amount of oil in the engine, if your change intervals are reasonable, that perhaps 2 litres of oil left in the system on each change will not really impact the overall cleanliness. Get the oil tested on oil changes and you can see exactly how "dirty" the oil really is, you can make a call then.

As for running the engine without oil, I noticed the comment "no damage done". How exactly was that assessment determined? It's possible that caused the equivalent say of 5000 miles of wear in 20 minutes, or did some long term impacts that, while not causing an immediate failure, can prematurely shorten the life of the engine, or even cause wear that will only show up under very stress. I for one would not risk that with my 993 engine.

BTW, its good practice to crank the engine after putting in 7 litres with the DME relay pulled to fill the filters and pressurize the system. Crank until you see 1-2 Bar on the oil pressure gauge. I then put in another 2 litres, and start the car for 1 minute or so, checking for leaks. You can put in the last 1/2 litre right there, and then top it up when the engine is warmed up fully. I keep the oil at 1/3 full, no more, that seems to be a good sweet spot. Some engines gobble oil until this spot and then slow down, and it also allows for the oil to expand without over filling when the engine is running hot.

Cheers,

Mike

Quadcammer

brilliant.

here's what you do. just leave the drain plug out. Run it long enough, and the thermostat will open. At that point, some oil might come out, or a rod. Either way, you've accomplished something.

nine9six

So what exactly is going on here? Do some post crap like this just to see their own avatar and advance their post count number?

This and the post by AKTUNG seem to be either lost attempts at humor, or just simply devoid of any thought. Which is it?

Quadcammer

uh, what?

I don't torque the engine drain plug. I've done enough oil changes to have a good feel for when the crush washer is well enough crushed.

nine9six

Which is WHY I posted the question to begin with...
Only thing is, I didn't need to have done "enough oil changes" to question the tech spec of 40 ft lbs.

Alum plugs in oil tank and engine drain plug; along with the Porsche specification of 40 ft lbs., were enough to prompt my question to the group.

Really! "hand tight" as like in oil filter hand tight? Perhaps he should think about authoring techincal specifications.