I have a 1998 Pontiac Grand Am with the 3100 V6 engine and automatic with 90K miles. It has an intermittent noise that I can only describe as a grinding or scaping noise. I seems to be coming from one of the accessories driven off the serpentine belt. If I had to guess it seems like it's coming from the water pump. It's driving me crazy because it comes and goes. One minute the car will sound like it's about to seize, and then the noise will suddenly stop and the engine will idle smooth and quiet. After a few minutes the noise will slowly start to build again. Some days it never makes this noise at all. It's been doing this on and off for 4 or 5 months now and I'm afraid that eventually, something is going to fail dramatically, but I just can't find the source. Anyone have an idea what this might be?
Thanks in advance, Vinny