Squeak, squeak

My 98 Continental is squealing pretty bad. I've had it in to the shop twice now, the first time the replaced the radiator cap saying it was leaking a bit. It stopped for a while, then it started again. the second time (different shop) they replaced the idler pulley, tensioner pulley, and put a new belt on there. It stopped sqeaking for about a week and gradually starting again, at first only after starting and now it's constant. This is really angering me and I'm tired of wasting money in the shops for it to just keep doing it. I am open to any ideas of what it could be and/or what could be causing it.

Can you tell if it's a belt squeak? If so, it sounds like your mechanics are heading in the right direction.

It's a bit tough to diagnose a belt squeak on the Conti. since there's not much space to maneuver in there.

The belt drives a number of components, any one of them can be squeaking, or causing the belt to drag thus causing belt glazing, and the squeak.

You'd have to remove the belt, individually check each component the belt comes in contact with, and if they all pass inspection, replace the radiator cap, NO.. just foolin' but, if the mechanic can't find anything obvious, he'll be guessing at the cause. Could even be the tensioner spring has lost it's ability to keep the belt tight.. could be a shitty brand belt that's prone to glazing.

Back in the old days, we used to use a belt dressing on the glazed side of the belt to stop the squeak. Some even used a bar of soap, rubbed it on the belt as it was running......

I had that same problem before.
Squeaked for a little bit, so got the tensioner, idler, and
belt changed. The squeak went away for a while, than
came back again.
I come to find out that it was my alternator squeaking.
You should get yours checked.