2004 Chrysler Town and Country Engaging air condition cause

Is it a squealing noise or squeak when you hear it?

It is neither actually, it is more of a rumble. Almost sounds like a pulley is loose but I can't find it. The Ider pulley seems solid. The tensioner was new about 6 months and I double checked it to see if it was still tight. I put a new water pump on about 1 year ago and it seems tight.

When I have the air conditioner on and I have the vehicle in park or neutral, it does not make the noise. When I put it in drive with my foot on the brake, it makes the noise. It gets so noisy at times, I have to put it in neutral or shut the air conditioner off when at a drive up window. THe noise goes away when the RPM's increase.

THe only thing I can think of is the compressor itself has a bad bearing in it and is making noise at a certain RPM.

I have this exact problem on my 2000 T&C w 3.8L I am under the impression that the problem is either a fractured flexwheel(flywheel) or the lower engine berring. I have been told that the odds are its the flexwheel.

Is your noise from the front or rear of the engine?

It seems to be coming from the center/back end of the engine. I already tried replacing the A/C compressor and the mechanic said that the compressor was not the problem. Noise is loudest when idling with A/C on. Turn A/C off or step on gas and noise fades away. I thought it was A/C as well but now I think it is probably the flexwheel. Problem is I won't know for sure until they drop the tranny. If it is an engine berring instead, then I will need another engine.

I wish I could be sure of the cause so I can make an effective decision as to what to do.

Lets eliminate anything run by the accessory belt like the AC, water pump... Remove the serp belt and see if the sound is still there. NOTE: Only run the engine a few seconds or it will overheat. Just long enough to determine if the sound is still there or gone. Just so you know, a bearing will make a knocking sound. The flex plate will make more of a chatter. (It's hard to describe over the internet).

Try that and let me know what you find.

Joe

My dad has a van with the exact same problem. He has replaced the alt, idler pully, tensionor, and A/C compressor. Still have the noise. He has taken the belts off like Jacobandnickolas stated and still have the noise. Any advice will help.

Use a piece of hose to help pinpoint the location of the sound. The hose needs to be about 3 or 4 feet long. One end goes in your ear, the other end slowly move around the engine to locate the source of the sound.