Rattling sound and loss of power

Question

My brother's '85 Toyota Camry with ~190k miles started making a funny rattling sound and lost about a quarter of its power. The rattling seems to come into play when it's under load, like when he's going up a hill or trying to accelerate strongly. It sounds like it's coming from the transmission.

It sounds like it could be a bearing but that wouldn't explain the power loss.

What kinds of problems could cause these symptoms?

Answer 1

My brother said that it ended up being the timing belt; he assumes it was broken teeth. He didn't really care why because he only needed it fixed enough to pass a "cash for clunkers" program.