Cadillac Repair: 1985 cadillac fleetwood several problems, 1985 cadillac fleetwood, crank pulley

Question
Hi, I have a 1985 cadillac fleetwood fwd and have been having these reacurring problems:

1) car makes a loud squeeking noise coming from the timing belt/ crank pulley (alternator, timing belt, crank pully all replaced recently and didnt fix the problem)

2) car idles when at a red light or in traffic, shakes and then has trouble shifting gears (automatic transmission)

3) Car makes a loud tick noise when it is turned off that lasts several minutes, sometimes up to 15.

I recently had the valve cover cover gasket replaced, and was told this would stop an oil leak causing most of the problems.. and it seems i wasted 500$ on this mechanic.. any help would be greatly appretiated.

Answer
1. Spray the belt with silicone spray and if the noise returns, replace the belt.

2. IS or HAS the check engine light ever illuminated on the dash while driving the vehicle ?.

3. Sounds like a faulty IDLE SPEED CONTROL MOTOR.  But I would have to hear the noise.