JaredSi
New Member
Hello all,
I have a 2004 KJ w/ 3.7 and 150k. At idle when the AC is on, there is a very loud knocking sound that sounds like it's coming from the AC compressor. It also only manifests itself when the engine is warm. The sound will go away immediately with any amount of throttle. I've replaced the idler pulley, it was worn and gnarled but not the cause of the sound. I then tried to replace the entire tensioner assembly but that did not fix the issue either so I returned the assembly.
I should mention the AC compressor works great and is blowing very cold air, consistently. The clutch is not clicking on and off rapidly. I ordered a new clutch/pulley set for the AC and set about installing it today. I noticed that the old clutch is very unevenly worn on one side. The pulley seemed to be in good shape though with no play or sound from the bearing.
However when installing the new clutch the old spacer does not give enough clearance and the spacers that came with the kit do not fit. So I reinstalled the old pulley/clutch and even though I cleaned everything and lightly tapped on the pulley with a mallet, the sound returned and did not change at all in tone or frequency. It is not a sound that is consistent or one that matches the engine frequency.
What do you think could be the cause of the sound? I suppose it could be the AC Compressor itself but considering how well it works I'm doubting that. Since it does work so well I'm hesitant to have it flushed and recharged as I'm afraid if something is wrong with it, I'll have to replace the whole unit.
Thanks!
I have a 2004 KJ w/ 3.7 and 150k. At idle when the AC is on, there is a very loud knocking sound that sounds like it's coming from the AC compressor. It also only manifests itself when the engine is warm. The sound will go away immediately with any amount of throttle. I've replaced the idler pulley, it was worn and gnarled but not the cause of the sound. I then tried to replace the entire tensioner assembly but that did not fix the issue either so I returned the assembly.
I should mention the AC compressor works great and is blowing very cold air, consistently. The clutch is not clicking on and off rapidly. I ordered a new clutch/pulley set for the AC and set about installing it today. I noticed that the old clutch is very unevenly worn on one side. The pulley seemed to be in good shape though with no play or sound from the bearing.
However when installing the new clutch the old spacer does not give enough clearance and the spacers that came with the kit do not fit. So I reinstalled the old pulley/clutch and even though I cleaned everything and lightly tapped on the pulley with a mallet, the sound returned and did not change at all in tone or frequency. It is not a sound that is consistent or one that matches the engine frequency.
What do you think could be the cause of the sound? I suppose it could be the AC Compressor itself but considering how well it works I'm doubting that. Since it does work so well I'm hesitant to have it flushed and recharged as I'm afraid if something is wrong with it, I'll have to replace the whole unit.
Thanks!