GwynnieMae

pp000830

Are you possibly overfilling the oil where the excess is being consumed by the intake where it collects and gets all over the place?
If so you are not alone in this, a very common situation.
I ran across the following comment in the 993 Rennlist Forum:
“How full do you keep the oil tank? When I kept mine at the full level I'd go through easily a qt. per 600 miles, now I keep it at min - 1/4 I use barely a qt. every 2500 miles. Even now, after spirited driving, the oil can expand to over 1/2 full.”
The implication here is that a true measure of a full oil tank is somewhat variable and overfilling may be an issue for some.
I may also contribute to an erroneous perception of an oil leak, a faulty air injector system due to clogging, or even the conclusion of an oil loss due to valve guide issues prompting an unnecessary top end rebuild.
These days when I change my oil I fill it to 1/3 of the fill range on the dip stick with a running very hot engine.
Andy

Endoman

As said most common cause of oil in the inlets is over fill. My inlets are off and I have a coating oil probably due to crankcase pressurisation (it's a 170k engine). I have similar oil stains around the flap valve, there are small oil seals each end of the shaft which are cheap and can be replaced. All high milage engines will have this to some extent. Your tank breather will probably have a coating of gunge. My 993 had a lot of use commuting last year so rarely got up to full working temperature which does not help. I wouldn't be too worried if leakdown is good and the engine stops smoking when it warms up. I used to get an occasional brief puff of blue smoke from cold but it soon ran clear. It's a '94 so same inlet same oiliness but not quite as bad. The crankcase breather to pipe gasket was leaking a bit as well. Mine would benefit from at least new rings and a head job but it will have to wait.

Railmaster.

True! True! True! Don't ever overfill! But how low can you go? Staying at the low mark on the stick, is that OK? I bet it is!

I change oil once a Year and fill up to 2/3 and then I drive the whole season and never check the oil again! I'm pleased if I see the oil level nedle move just a tiny bit when the engine is hot!

GwynnieMae

Railmaster.

One mans fill is another mans overfill! Did You go above 2/3 of the empty-full scale on the dip stick?

Then You have probably overfilled the oil!

Kein_Ersatz

pp000830

The total range of the oil fill on the dipstick may be a quart. The car holds about 12 quarts of oil and ten of them are refreshed at an oil change. With this in mind, I would think if oil registers even at the bottom of the fill range on the dipstick there is no real risk of loss of lubrication due to underfilling the oil on a street driven car. Remember the engine is a dry-sump oil system where there is this big reservoir of oil at all times in the oil tank.
Do others care to comment on this?
Andy

pp000830

Oil most likely leaking out of the intake manifold, dripping through the engine sheet metal onto the cylinders. If the cylinders were leaking it would be wet on the bottom of the engine not on the top of it.

GwynnieMae

Endoman

Hopefully not the through bolts, from the state of the inlet manifold I would think a lot has been coming through the resonance flap shaft oil seals, Generic G8x12x3 or Porsche 999.201.371.00 good thread here:- https://rennlist.com/forums/993-foru...-manifold.html
messy on variorams.

nine9six

This^^^

Churchill

OP that doesn't look too bad. Through-bolt o-rings are under a great deal of oil pressure so if they're bad you typically get a real oil leak or real dampness, not the kind of built-up crud you have. I had a resonance flap leak on my Vram and it was messy. Thought it was a much worse than the manifold, but it was just that tiny o-ring.

zelrik911

The seals on the Resonance flap bearings will be worn and oil will drip out if you have any blow-by pressure in the manifold. Otherwise the normal manifold vacuum will be reduced because of that leaky resonance seal.

I was interested to hear that the flap bearings can be replaced cheaply as I need mine to be done.

Endoman

Not the bearings just the seals are cheap (about $3). I got them from a local bearing supplier and they are the identical SKF ones that came out. The oil on those cylinder fins is the typical appearance of oil misting rather than a persistant drip.