Lots of oil in the intake, any ideas??

[RetroSC]

My 90 C2 used to be fairly dry, but last year it started leaking from what appeared to be, well, everywhere! Front, back, sides, top, bottom... it looked like all seals gave up the ghost at once. However, upon further investigation it looked like all the leaks were originating up top, on the bottom of the intake then running down all over the place. So I opened up the intake and sure enough, oil was everywhere and was pooling at the bottom of the manifold.

Surprisingly the car doesn't smoke at all, not ever after sitting for long periods. I even had a friend follow behind and watch closely on acceleration and deceleration, nothing.

So what gives, how could all this oil end up so high in the intake? I see two hoses coming from the oil tank that tie into the intake, one for crankcase ventilation I assume, but what's the other small one?

One last clue, if I fill the oil when warm to mid dipstick, it seems to leak much worse. I have to run about 2 quarts low all the time, otherwise I get so much oil leaking that it starts to smoke at stoplights.

[DRACO A5OG]

Over fill of oil, what is the oil level when she is hot and at idle? not warm but hot.

Check to insure dipstick is the correct length.

[RetroSC]

Maybe, but I don't think so. I've been fighting this for about a year now and run the oil really low, still have the issue. Hot at idle I only fill it until it just touches the bottom notch, about 2 quarts low best I can tell. If I fill it to the middle things seem to leak much worse.

[DanielDudley]

What oil are you using ?

[DRACO A5OG]

Have you replaced the breather hoses coming from the oil filler neck, should be similar design, no?

[RetroSC]

Brad Penn 20/50.

No, haven't replaced any hoses. I've had a number of older 911's, but this is my first 964, so I'm not sure what the purpose of the two hoses are, vs just one, but I'm wondering if one of them were clogged or something and I'm getting positive pressure in the tank and it's feeding back through these hoses??

[Lyle O]

Originally Posted by DRACO A5OG

Over fill of oil, what is the oil level when she is hot and at idle? not warm but hot.

Check to insure dipstick is the correct length.

+1, as Draco says, make sure you have the correct dip stick. It sure sounds like the one you have is too short, or it is not fully pushed into place.

[RetroSC]

That's a good thought on the dipstick. I checked and looked at pics online of 964 dipsticks, that's the one I have. It's fully seated as well, and also corresponds with the dash gauge, i.e. if it's at mid level then the gauge reads mid level. The way I run it now the gauge just starts to move, but is at the very bottom of the range, same for the dipstick. (All checking done at warm idle btw)


I'm really feeling like I'm getting positive pressure in the tank or something and it's bleeding backwards via the breather hoses?

[Steve@Rennsport]

Do a leakdown test to make sure your rings & pistons are all healthy.

[Jack Olsen]

Is the cone-shaped restrictor present? What happens to your idle when you open the oil tank up?

[gazzerr]

Do these cars have a PCV valve? It might be that.

[RetroSC]

Originally Posted by Jack Olsen

Is the cone-shaped restrictor present? What happens to your idle when you open the oil tank up?

Not sure, where would I find it?

I'll have to check on the idle when I get it back together, but I don't recall it changing much when opening the tank fill.

[RetroSC]

Originally Posted by Steve@Rennsport

Do a leakdown test to make sure your rings & pistons are all healthy.

Wouldn't I have a smoking issue then, and likely oily plugs? And would type of issue bring this amount of clean looking oil up so high in the intake?