damper pulley noise

Someone gave me a 1988 pontiac bonneville as a present.
The car vibrates and shakes a bit in idle and i hear a noise from one of thr pulleys.
Not sure where exactly but it sounds like near the power steering pump
went to 3 garages ,
2 said the damper pulley is noisy and needs replacement.
the other said the noise is from the power steering pump.
the car only has 135000 km.
body a1.
i know nothing about fuel injection.
one of the garages told me the crank pulley and crank sensor should be changed.
$600 to fix.
what happens if i do nothing.
they said they had to pull the front wheel shaft off to do the job.
How is a crank pulley changed on a 1988 bonneville?
could you guys help me out .
i need some advice.
is it time to start looking for a brand new car.
the mechanics i have dealt with are a bunch of idiots or crooks.
mechanics have a tendacy to fix one thing and then an another problem creeps up.
the mechanics pit of hell.
i must have seen 20 mechanics sofar and they all look the same.
they all look half stoned.
dont listen to what you tell them .
dont read the service manuals you supply them.
its like talking to a brick wall.

Hey Guy, I just read your post and I had to laugh at your low opinon of mechanics. Now I know how the lawyers feel. Sounds to me like you never met a real mechanic. There are some out there who take pride in their trade.
About your damper noise. Remove the serpintine belt, start the engine and see if the noise goes away. It could be the idler pulley, alternator bearing, water pump, AC clutch, or it could be the belt itself.
The 3.8 and 3.1 engines did make some noises such as an exhaust rattle from the schrouds that cover the manifolds. The injectors sometimes sound like a spark jumping. Very seldom do vibration dampers give you any problems.

Hey Guy, I just read your post and I had to laugh at your low opinon of mechanics. Now I know how the lawyers feel. Sounds to me like you never met a real mechanic. There are some out there who take pride in their trade.
About your damper noise. Remove the serpintine belt, start the engine and see if the noise goes away. It could be the idler pulley, alternator bearing, water pump, AC clutch, or it could be the belt itself.
The 3.8 and 3.1 engines did make some noises such as an exhaust rattle from the schrouds that cover the manifolds. The injectors sometimes sound like a spark jumping. Very seldom do vibration dampers give you any problems.
it was the vibration damper.
the crankshaft pulley was taken off and repaired.
the crankshaft pulley is composed of metal on the ouside and plastic in the inside. an arc welder was use to weld the plastic and metal together.
a spot weld was done 1 inch by 2 approximately.
very seldom you said.

Interesting..something to learn everyday....would have been fun to have a photo!
Glad you're back on the road...