Noisy air conditioner

I have a 2000 Chrysler town and country mini-van. the airconditioner in it was making a very bad rattling sound when it cycled on. This noise happened only with the compressor engaged. my mechanic replaced the compressor, accumulator and orefice. STill the same noise. I have also replaced the water pump,belt tensioner and idler pully. still noisy can’t figure out why…help

Has anyone checked the blower motor and squirrel cage to see if they are filled with leaves and debris?

“Has anyone checked the blower motor and squirrel cage to see if they are filled with leaves and debris?”
"This noise happened only with the compressor engaged."
CSA

This time of year, when the fan is on, so it the compressor. But maybe frenchman will post back and let us know how he determined that the noise only happens when the compressor is engaged. Did he have the hood open and watch the compressor cycle?

Yes the noise is under the hood. If I don’t turn the a/c on, no noise. I can run the vent on high or low. no noise. just when the a/c is engaged. I have taken the van to the dealer and they say it is something in the transmission. However I have a problem believing this because of the cycleing. The noise is similar to something hitting a fan. (nope that’s not it either)

I would do this: Release the belt from the tensioner. Put a mark across the two halves of the tensioner so that you know where the end of the tensioner’s travel is. Replace the belt. How close is the tensioner to the end of travel?

I drove myself crazy with this exact kind of problem (different van). My OEM tensioner went kablooey after it had been rattling for a while. I bought a new Dayco tensioner & replacement belt. The rattle remained - so I drive myself crazy for a while about it and then finally realized that somewhere in between GM & Dayco the specs were off by a bit & the tensioner ended up very close to its stops with the belt installed. The AC load got the stops rattling together.

Here is a thread I made about it - asked & answered by me: http://community.cartalk.com/discussion/2142135/rattling-belt-tensioner-again/p1

The noise is not related to a radiator cooling fan is it? Sometimes blades crack or distort from heat and heat the radiator or fan shroud.

To ok44550 I did check the cooling fans. they are a bit noisey but not the probem. Thank you cigroller, I will check into the tensioner, as I stated earlier I did replace the tensioner and belt, but I will check to see what the travel is on the tensioner and go from there. Thanks,

My mechanic called and told me it is the flexplate. it is nearly broken off. He will have to pull the tranny and replace. thanks all for your comments.