My recently purchased 2000 has an extremely irritating vibration at idle when the ac or defrost is on. It almost sounds like subwoofer bass. More concerning is the knocking sound at idle that seems to be coming near the console around the automatic tran shifter or transfer case shifter. It almost sounds like pebbles bouncing around. Could this be transfer case chain slapping around? 4x4 and tranny are both smooth?

I would really appreciate any suggestions.

 

I can not help on the first sound (ac related) but the second sounds like my transfer case shifter that rattles sometimes. If I pull up on the lever slightly or hold the shift lever towards the passenger side the noise stops.
I've not found a cure for it but it's good to know it's nothing serious.

btw welcome to CF!

 

Thanks! In regards to the ac/defrost issue, something obscure came up in a google search stating that on 00-01' xj had a recall for a similar sounding issue that involved a mod to the ecu? Sound familiar to anyone?

 

I did alittle searching and found this thread that may be related:
https://www.cherokeeforum.com/f2/fan...bration-25405/

The electric fan may or may not run when you use defrost and/or AC. It's possible the electric fan is loose, has a broken blade or is not mounted correctly. ***You could watch the e-fan while it's running and see if it's wobbly or making the noise, just be carefull !!***

Good source tells me the e-fan may not come on with AC/defrost.
"00-01 efans are temp sensitive only (218F)."

 

Not familiar to me but it's a mystery to me how the ecu would cause a heavy vibration.

 

I just replaced my efan blade because I was getting an annoying noise from it. At first I thought it was electrical because it was sort of a pulsing noise. New blades took care of the problem.

 

From the dealer mike or auto parts store?

 

I replaced it with the original blades that came with it because the one I bought from a member here( I just needed the motor) had been cracked and broken from a wreck he was in I guess. So I used the motor and shroud from his setup with the blades off of my original setup. Not to mention I wired it up on a toggle switch and relay to use at any time.

 

edited my post above. now reads
"00-01 efans are temp sensitive only (218F)."