mm wrote:

Your compressor is probably toast. I've heard that dreaded sound
many times and had to deliver the bad news to the owner.

TDD

It may be a good thing. I was flirting with only replacing the
furnace, since I use the AC so little. But I'll do both.

As little as you use the A/C, consider a used compressor - no more than
three years old. You can save 3-4,000 bucks.

I see 'em often on Craigslist.