A/C Noise & Compressor Ticking....2002 Pathfinder

[JPMGM]

Greetings, Just recently I noticed a low "roaring noise" immediately after turning on my A/C. It fades away in about 5 seconds and my A/C runs fine. Also, I have noticed a ticking noise originating from my A/C compressor ~ I have had this corroborated by my local dealer and a wrenchhead friend.

In my short research, the roaring noise is symptomatic of a faulty A/C compressor. Would this be correct? Any thoughts if the "ticking" from my compressor is also reflective of a faulty compressor? I have 45K miles.

Thanks for the help guys!! This forum is great!

[NISTECH]

yea noise from the compressor is typicaly an indication of the compressor going out, though I have seen quite a few of the idler pulley bearings go out. The roaring may be just that idler pulley. Use a long screw driver and place it on the nut of the idler pulley for that belt and put your ear on the handle,listen. Then do the same by placing the screw driver on the body of the compressor. Where is the sound louder? If its at the pulley your pulley bearing is worn. Replce the pulley. The ticking may be related but it could also just be the compressor clutch rattling, they do that after several miles on the car.

[JPMGM]

Thanks NISTECH, I'll do that once Katrina blows through. One more thing I failed to mention, the dealer service dept. told me that the belts can make that noise if they are going bad ~ I just replaced both belts 1 month ago. I'm a little skeptical on that one. The screwdriver test will clear things up. I would have never thought that the pulley could be the issue. Hopefully that is it.

thanks again.

[NISTECH]

The idler pulley bearing failure is alomst always caused by a recent belt change and a slightly to tight adjustment on the belt puts excessive load on that bearing.

Stay safe during the storm, Hope all is ok after she passed!!

[JPMGM]

Montgomery (AL) will get some rainey, blustery weather. Possibly some tornados.

Would you happen to know the appropriate torque for the idler pulley (a/c)?

Thanks again.

[NISTECH]

I was reffering to belt deflection nut pulley nut torgue. Just make sure you can rotate the belt about 1/4 trun once its set then tighten your nut, and recheck the deflection. The check should be done at the longer distance between pullies.

[JPMGM]

The ticking noise was a faulty belt that was coming apart. Sounds like new after replacing the faulty belt with a new one.

Had no idea that belts could make such a bad noise....

Thanks again.

[NISTECH]

I take it you made it through the storm ok since you posted back. I was wondering about ya yesterday. Glad to see your alright.

[donald]

hey, first, sorry for raising the dead, but on a similar topic, I was curious how critical is it to change idler pulleys?
I ask because it seems to be such an expensive part for a relatively simple looking part...

AC pulley

PS, Alt, Fan Pulley

[Transtek]

I had a problem with belts and a/c idler pulley squeling. Put on new belts, but no change. So I took the idler pulleys off, cleaned them up and greased them up with heavy duty bearing grease (after checking that they were okay by rotating them with your fingers). Reinstalled, making sure to put the spacers in the right position! and it all sounds like new again! Hope that helps, as it may be your problem or at least can prevent the bearing from seizing up! Oh, and make sure to tension your belts as per the manual.

[ARKQX33V6]

Transteck, did you have to take a shield cover off the bearing in order to grease it?

[Transtek]

Transteck, did you have to take a shield cover off the bearing in order to grease it?

If you mean the shield cover that protects the pulley, then yes, that comes off anyway when you take off the nut. Just make sure you get it back on the right way so it doesn't foul the rest of the pulley and with the spacer underneath it.
If you mean the plastic cover on the bearing itself, no I didn't remove it. Just cleaned and greased around the edges and center so that the axle on which is slides is well-lubricated. I guess you could take it apart, but TBH I'm no expert mechanic and thought it better to leave it be and it worked fine afterwards!
BTW you can check the bearing when it's off by spinning it on your finger. If it spins freely then its OK. If not and needs replacing you WILL need a new one (it cannot be seperated from the pulley as I erroneously stated before). Anyway, better off giving this a try for a few cents first before laying out loads of money.

[donald]

you can take the idely pulley apart? I was under the impression that the bearings wwithin the pulley were "sealed"...

[Transtek]

you can take the idely pulley apart? I was under the impression that the bearings wwithin the pulley were "sealed"...

Yes, your right. Old age is obviously affecting my memory!! The bearing in the pulley itself is sealed, but it is possible to clean it up and grease it in the middle where it rotates. This will at least prolong its life if the bearing is okay. And it stopped mine from squealing.

[ARKQX33V6]

Transteck, to be certain on my 97 Q the bearing within the idler pulley is a stock Japan made bearing with 2 sealed edges built into the bearing. The idler comes off very easy because the ID of the bearing is slightly bigger than the shoulder bolt OD that the bearing sits on. You took the bearing out, checked it wiped it then greased the shaft or shoulder bolt and all was quiet. Is this correct?

If the above was done then I have exactly the same situation, but I did not grease the shaft because in my mind the inner race of the bearing does not rotate on the shaft that it sits on. The bearing itself was removed in tact within the pulley, cleaned and then replaced.

No load running idle to 3000 RPM no noise, but with the compressor on about 1/2 as noisy as it was.

I was curious if the bearing itself is good at no load but when loaded is rough. It spins freely without wobble between my thumb and index finger.

So according to your results I need to grease the shaft that the bearing sits on.

In looking and working on the idler for the A/C, I have doubts about Nissan's thought pattern:
Why use a bearing if the shaft is the part of the rotational forces?
Why would you design an idler pulley to be uni directional, because if installed the wrong way around the nut tightens up the pulley so it cannot rotate when the outside washer is installed.
What purpose does that big washer provide? Dirt, dust prevention, the bearing is sealed. Support, the bearing is free to rotate.....

Regarding prices. A new bearing /pulley assembly was quoted around $ 79, Go to www.rockauto.com and check out their prices.

Often a sealed bearing must have at least 1 side seal removed and repacked with grease. This was my expectation to resolve the noisy idler issue. But greasing the shaft is an odd one, I'll try it and let you know and thanks for the input.

[Transtek]

I think you've got it right about what I did. As I said I'm no mechanic, so just cleaned, lubed the parts with grease, including the shaft (as you say, the logic to this one seems a bit strange but at least it will stop it seizing up over time!).
All back together, tensioned to the specs mentioned in the workshop manual, and that was it. Just make sure the dust cover/shied (bit black tapered washer thing) is not rubbing against the face of the pulley, as that would make a sound like a bad bearing as well. The tapered face should face outwards with the spacer behind it and the nut on top of it.

[ARKQX33V6]

Transteck, I did as you suggest and it quiets the idler down. I agree with the unusual task of greasing a none grease piece of equipment.

The order in which I discovered the idler as from back to front was spacer, bearing, big flared washer and nut..

Greasing just the spacer, no good but removal of everything and greasing the shaft or the bolt, the spacer and the washer and reassembling and torquing the nut after setting the tension the whole thing quieted down, but with a stethoscope you can still hear a bit of noise but sitting in the front seat it is quiet.

Again thank you for the help.

[Transtek]

Transteck, I did as you suggest and it quiets the idler down. I agree with the unusual task of greasing a none grease piece of equipment.

The order in which I discovered the idler as from back to front was spacer, bearing, big flared washer and nut..

Greasing just the spacer, no good but removal of everything and greasing the shaft or the bolt, the spacer and the washer and reassembling and torquing the nut after setting the tension the whole thing quieted down, but with a stethoscope you can still hear a bit of noise but sitting in the front seat it is quiet.

Again thank you for the help.

Glad it worked for you as well. Completely illogical as we have both mentioned, but obviously Pathfinders work in mysterious ways!