Oil on Clutch?

I have a relatively new clutch (13 months, 6,000 miles) that has begun slipping. This slipping began shortly after I had an oil leak around the oil pressure sensor. My mechanic says that oil likely leaked into the transmission and is causing the slipping. He said that I should keep driving it for 300+ miles and hope that the oil will burn out on its own, fixing the problem. Does this seem likely, or is my transmission a doomed?

(a few other details: its a manual transmission. I drive a stick fine-- the first clutch lasted 90k. I drive very little, so 300+ miles may take over a month)

Year, make, model??

Is it slipping constantly in high gears, or is just just a little slippery when you’re trying to get it into gear?

I’m not familiar with the engine compartment on this car, so the leaking oil pressure sensor could be an issue if it is oriented in such a way that it can leak onto the clutch. But if he fixed that leak, the clutch issue should go away in a matter of tens of miles at the most, not hundreds.

The much more common source for oil on the clutch is a leaking rear engine seal, which unfortunately involves removing the engine or transmission so it might be a bit pricey.

Piecing together clues from his message, name, and tags I have surmised it is a 97 VW Jetta.

Thanks for all the speedy replies–here are a few more details:

Greasy Jack is a good detective. It is a 97 VW jetta. white.

The oil pressure sensor has been repaired (it was leaking visibly, and we replaced the part. Since the repair, I’ve noticed no oil leakage either around the sensor or any loss). Hence, I don’t think its a leaky rear engine seal. Also that was replaced 6k ago at the same time the mechanic did the previous clutch.

I think part of the the transmission about a foot directly below the oil pressure sensor. Quite a bit of oil leaked that direction, so I can imagine that some seeped in.

As far as symptoms go: If I’m at freeway speeds and I hit a steep hill, or accelerate quickly, the RPMs will race for a split second, before something seems to catch (at which point the RPMs will return to being appropriate to the actual speed of the car). All this, without changing gear.

My main question is really whether just driving will actually leaked oil out of the transmission.

oh, one more thing. This isn’t happening that often. Just often enough that I delude myself into thinking that I am crazy and there is no problem, and then it happens again.

Unless the oil pressure sensor is located directly above where the transmission attaches to the engine, I don’t see how oil could have leaked onto the clutch.

If, indeed, there is oil on the clutch it is more likely to have come from a leaking rear main seal. Was this seal replaced when the new clutch was installed?

A slipping clutch doesn’t mean there’s anything wrong with the transmission. They are separate.

I can’t type today:
Should be: My main question is really whether just driving will actually burn leaked oil out of the transmission/clutch?