Needing a 2nd opinion here. 2001 Ram Van 1500, 3.9 V6. Noticed a rattle under the hood a while back, progressively getting worse. After some research and physical investigation under the hood, it seemed my tensioner pulley was doing a dance that matched up with the rattle. Replaced the assembly yesterday......rattle still there! Started new investigation, I noticed it stops when I turn the A/C off. I'm thinking clutch bearing now. Can this be replaced on the vehicle? Any instite to the process is welcome. How many parts do i need to remove under the hood to get this job done?

 

The clutch bearing only turns when the A/C is off. When the A/C is on, the two halves of the clutched are locked up and the compressor shaft starts turning. It's the compressor itself that's giving you the noise, not the clutch bearing.

 

Is there a way to verify? If Pull the belt and free spin the pulley I should hear the noise, yes? I may be stating the obvious but if Its the compressor itself, I am looking at replacing? The A/C seems to be working fine, if i just let it go until it gives out am I looking at any adverse affects?

 

New twist.....I may be a bit luckier than expected at least as far as having to replace a compressor. By a stroke of luck I have managed to determine the rattle is more near the tensioner pulley like I thought in the begining. It does only happen when i turn on the A/C however it increases and decreases with the fan motor speed. The strange thing is I cant really hear it inside the van. Anyone have any ideas? I have a single A/C system but I have a front and rear blower, the rattle only happens when the front fan speed is adjusted.

 

Check your clutch fan for any looseness. Might need to remove the belt to check but any up/down and/or side to side play means that the water pump and or the clutch fan bearings are bad.

 

If it was the fan clutch, would the A/C compressor have an affect of when it rattled? guess its an easy check, looks like that will be the next thing. I pulled the A/C blower motor hoping that was where the rattle came from, no such luck. Unit works like a charm all speeds with no strange noises. Thanks for the suggestion, I will post results.

 

In short yes it can have an affect. Also check the idler pulley as well.