Volvo: Volvo not starting, volvo 850 wagon, car leaks

Question
1995 Volvo 850 wagon. Engine not turning over at all - no clicking sound - battery has a full charge, radio & lights are fine.
Makes an odd sound...kind of a constant swooshing sound when the key is turned to start position. Sound seems to be coming from the area under the power steering pump - around the A/C compressor, perhaps. I've never heard this sound.
Any ideas?
By the way, it's my son's car & leaks oil like a seive, but is too expensive to fix the seals, we're told. He reported having previous troubles starting when very low on oil.
I looked for answer in the past year but didn't see one that seemed to apply. Thanks a lot in advance for your help.

Answer
Hello Steve! Coulb be a problem with the starter no engaging. I have heard them make that kind of sound. Also could be a problem with the valves in the cylinder head stuck, causing low compression. It is best to have a Volvo technician look at it.

Jimmy