Oldsmobile/Buick Repair: 88 olds cutlass cierra engine noise, crankshaft damper pulley, cutlass cierra

Question
Hi, I am helping a friend work on her car. It is a 1988 olds cutlass cierra with an engine rattling sound. At first I thought it was her water pump bearings, but I took off the serpentine belt and started it and the noise was still there. The niose is like a rattle/knock that speeds up and slows down with the engine RPMs. I dont think she can really notice it when she is driving around but it is definately noticable when the car is at idle. I know it's not much info to go on, but do you have any idea what might be the cause? I would appreciate any insight and thanks in advance for your help.  

Answer
Hello Dion,
88 may still have a heat riser valve in the exhaust manifold, and they would rattle now and then.
Other exhaust pipe rattles from touching the frame are a possibility.
Rattles inside the catalytic converter.
I have heard rattles due to a loose torque converter on the flex plate, and even a cracked flex plate.

Is there a separate belt for the power steering pump?

Then there is the possibility of internal engine rattles. A long screwdriver heald against your ear, and touched to spots on the engine can act as a stethescope, or you can buy a mechanics stethescope.

Timing chain can rattle in the front of the engine, and the crankshaft damper pulley can rattle if it happens to be loose.

Hope some help here for you. Good luck.

Van