Dear Tom and Ray:

Two summers ago in my 1987 VW Jetta, I noticed that a brown spray appeared on the underside of the hood above the AC unit. Last summer, the AC went dead and I had a mechanic look at it. He said that the Freon level was fine. A year later, I tried the AC again and it worked, but the brown spray is back again. What is going on?
Ronnie

RAY: Your air conditioner is kind of like me and my brother, Ronnie. It's working at the moment, but it probably won't be working for long.

TOM: The air conditioning compressor has two substances inside it. Freon is one of them; that's the refrigerant. But it also holds oil, which lubricates the compressor. And that brown spray you see is probably the oil from the compressor spraying out all over the engine.

RAY: My guess is you have a bad seal. And if you don't fix it, all the oil will eventually leak out. When that happens, you'll see so much smoke, you'll think my brother is making up a batch of his famous "cajun style" toast (that's "blackened" for those of you unfamiliar with nouvelle cuisine).

TOM: Once it seizes, you're going to have to replace the whole compressor. But if you catch it in time and fix the seal, you may be able to save it. Good luck, Ronnie.