My 99 PA recently developed a loud chattering noise when the engine is under torque. When in gear, stopped at a light or under light acceleration, I am hearing a loud chatter coming from one of the accessories on the front of the engine. I am curious if anyone else has heard a noise similar to this and which one of the accessories could be the root cause. I replaced the tensioner assembly and checked the pullies on the others, only to find just the water pump pulley with a little bit of play in it. Could this be it? Any known issues that resemble what I'm describing?

Thank your for any help!

 

The water pump pulley should have no ply in it at all. Even if it isn't the source of the noise it would be a wise move to replace it before it gets worse. And you know how that works, it gets worse when you lose the coolant in Walmart's parking lot or are miles away from home.
If you can have someone load the engine with their foot on the brake and in gear , just give it a little gas and see if you can create the noise, that might help to determine where the noise is originating.

 

Well... The water pump and power steering pump both had good amounts of lateral movement in their pullies, so I changed them. I still have that awful noise coming from the front of the engine. Sounds like someone shaking a tin can full of marbles. Harmonc balancer make this kind of noise? Any other thoughts?

Thanks

 

Here is something you can try.
Remove the belt, then start and load the engine in gear with the brakes applied.
You don't want to run it longer than necessary just to check since the water pump will not be circulating coolant. If you still hear the noise then it has to be coming from the engine itself. While the belt is off turn each pulley that the belt drives and feel for any noise or roughness. That could indicate the faulty part. Let us know what you found.

 

With the belt off, the noise is not present. It also isn't rhythmic with the engine rpms. Everything but the AC and alternator are new. AC and alternator both seem to be in good shape with no play in pullies or noise when spinning them. This leads me to the harmonic balancer. I had heard that was a common fail point on the 3800, I just didn't know what kind of sound that would make.

 

Here is something else you can try.
With the belt on, try to move the belt back and forth. There should be no resistance from the other parts ie. ps,alt, idlers,a/c. If you can move that belt then the crank pulley has lost it's inner insulator and will need to be replaced. You will actually be able to see the outer part of the pulley move maybe only a 1/4 to 1/2 inch, but that will be the source of the clacking noise.