95 SSEI has 240K miles. Yesterday the car began to stall, chug, and had little to no boost. As I backed out the filler plug for the SC oil i noticed a release of pressure (air sound). I added a very small amount of SC oil, started the car, and it ran great. Drove the car to work (18 miles), after work the same symptoms started again. This time it required a little more SC oil then the first time. Again the car ran as good as new. Heres the rub....there is NO visible sign of any SC oil anywhere on the exterior of the SC, or surrounding area, including the nose/pulley area. Where is the oil going? Am I looking at gaskets/seals, or something much more serious? BTW, there is NO noise/rattling/or play in the SC. This car has been treated with TLC, and has always been a soild performer. Thanks.

When you say you added some. Then topped it more. When was the last time you checked/changed the oil?

It is very odd that it is disappearing with no signs. How about some pictures of the snout and where the snout meets the intake manifold.

Was car on level ground both times you checked/filled the SC oil?
I checked the SC oil in all of the SC'ed cars at my parents place yesterday and found everyone of them was almost a half bottle low. Apparently it was a habit of the person filling the SC'* on the assembly line to put less than the required amount in. :?
When I pulled the oil fill plug on my 19k old SC there was no odor from the oil so I just added 1/2 bottle. Got to my moms 02 Park Ave Ultra with 80k on it and it stunk like nobody'* business. I used an old Wesleys Bleach White spray bottle to drain the old oil out and then filled it up with new oil.
Sorry to off topic, but did you change the SC oil recently -if it hasn't been changed it'* almost like throwing money away mixing the new oil with oil that is way overdue for a changing.

The SC oil was last changed approximately 40-50K ago. I will change the oil again on Monday. The car was level both times I added SC oil. The amount of oil that was added was minor both times (combined an 1/8th of a GM bottle if that). I'm confused as to why the car would run so rough with such a minor amount missing, when I'm reading posts of some folks adding as much as a 1/2 bottle. Once the fluid is up to the threads on the filler, the car runs great. Also, either my allergies are really bad, or my nose doesn't work because I don't have the bad smell everyone mentions, and the existing fluid looked OK. Again, just looking for some help before my mechanic has his way with me. Thanks again.

Lack of supercharger oil won't cause low boost unless the supercharger seizes up. And even a siezed up supercharger won't cause your engine to chug.

With 240 K miles it'* no wonder.
No sign of exterior leaking probably means interior leaking, ie. seals, into the intake.
It will suck it in under vacuum.

Should lubricate your internals pretty good.

It will not suck in under vacuum. Under vacuum, the rotor casing is still pressurizing, but bypassing. The gear case can't ever see vacuum. Leaking rotor seals will cause an OVER pressure.

Well....I'm really confused now. The car is sitting at the mechanics. We'll start with an SC oil change, look for any type of leak, and go from there. I'll keep you posted as to what we find. My mechanic is usually pretty good at helping me out with stuff I can't figure out. :?

I'd be more concerned with trying to wobble, pull, twist, and turn that supercharger pulley by hand. It should be smooth, relatively effortless, and silent.

I agree with Will - the only place the supercharger would leak is from the front nose.