Pathfinder makes whistling noise

Hi I have a ?99 Nissan Pathfinder. Couple of weeks ago it started making whistling noises when in idle. I replaced my drive belts and narrowed it down to my A/C belt. When I start the car without the A/C belt the noise is gone. When I put the belt on and tighten the idler pulley the noise comes back. And I think it gets louder the more tension I put on the belt. I went out and got an idler pulley from the dealer ($50!!!). Replaced it but the noise is still there. Any ideas? What else can cause that? I?m thinking about removing the A/C belt until summer, since I won?t need a/c here in Minnesota for the next several months. Will this disable something else in the truck or is the AC pretty much the only thing that will not function. By the way, a/c works fine right now. Thanks for any help / feedback

Reply to
Gene132
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A whistling noise is usually a vacuum leak. Is the motor running rough at idle?

Reply to
ppointer

It was running rough this summer and it stalled several times when I was sitting at a stop light. I took it in to a local shop, they couldn't replicate the problem. It never happend since. If it is the a vacuum leak, is it normal for the noise to go away when the belt is off? Thanks PPointer

Reply to
Gene132

Don't know the answer to your question. But a vacuum leak will cause the motor to run rough at idle.

Reply to
ppointer

I had this problem on a Mitsubishi- replaced only the AC belt and it squeeled like a pig. I took it back to Napa 3 times and each one squeeled the same (this belt cost $35). I went and got a belt from the dealer and the problem went away for good (the dealer belt cost $85).

Reply to
MM

Reply to
XcitableBoi

i was wondering how many posts itwould take before someone finally suggested its a bearing, im leaning towards the A/C one.

Reply to
Shawn

Bearing, a/c pump.

Reply to
Meat Plow

Ditto when I worked in the shop. People would bring in their cars that they had just serviced with aftermarket parts and complain about noise (belts) or poor running (inferior grade distributor caps & rotors or spark plugs/wires). Why people ever tried to run Champions in their Nissans was beyond us, but when they came in complaining of poor performance and they had just changed their plugs in the last

3,000-5,000 miles, it was always the first thing we looked for. Put in the standard NGK's, problem solved. Amazing. :-)

Changed out their parts for ours (genuine Nissan), problem solved.

Wil

Reply to
Truck

I believe your defrost uses the A/C. So, you may want to keep the belt on during the winter.

--Brent

Reply to
Brent

I gotta agree with you. I've always had better luck with factory parts for my Nissans and Toyotas.

Reply to
ppointer

Thanks guys, Here is the thing. Nissan dealer replaced my drive belts. And the idler pulley - bought at the Nissan parts store. So all are Nissan factory parts. Now, the A/C bearing that you are talking about, is it easy to get to, where is it located? And is it normal for it to make the noise even when A/C is off? Aprox. how much am I looking at to replace the a/c bearing? Thanks again for all the info.

Reply to
Gene132

Makes ya' wonder, don't it? LOL

Reply to
Jeremiah

Jeremiah, How do I get to it? Thanks

Reply to
Gene132

The bearing on the ac pulley is most likely the culprit, therefore, you will get the noise with the ac off.

Reply to
XcitableBoi

If it's the idler pulley bearing, it comes with a new a/c idler pulley assembly. How much? No idea, sorry. I'd `guess' between $65-$100 but I'm not really sure, it's been so long ago. If you're mechanically inclined, you can tap out the bearing from the idler and have it replaced, but you have to find a quality (think Timken) bearing provider, so usually it's far easier to just replace the assembly.

Wil

Reply to
Truck

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this is the part you are talking about, I already replaced it (sorry,I'm not good with parts and names :-))I think i said that in the first post, I got it for 50 bucks from thedealer. That's the first thing I suspected when I took off the A/C beltand the noise went away: bearing in the A/C idler pulley.Please tell me if that's not the part you are talking about.

Reply to
Gene132

the bearing he was referring to is the bearing in the A/C Pump, the pully is pretty hard to get off too. id just buy a used A/C pump from a salvage yard but if you dont trust that then maybe try taking the A/C pump to a mechanic and ask them to replace the bearing. just my 1 1/2 cents

Reply to
Shawn

And the winner goes to...... I took off my A/C belt again, made sure the other two belts are good. Started the car and heard a loud noise under the hood. When I opened the hood the power steering belt was almost torn apart and my harmonic balancer was hanging, ready to fall out. I took the pathfinder to the dealer, paid $214 for the part, plus labor and now it's like new. No noise, no squeaking. Couple of technicians looked at me like I was crazy when I told them this happened. One said that in his 10 year experience at the Nissan dealership this is the first time the balancer fell out. So I guess it's not normal for the harmonic balancer to slip like that, huh?

Reply to
Gene132

so my bearing guess was close ;-)

Reply to
doS

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