Changing Serpentine Belts

[Pwnin O'Brien]

So tomorrow I am going to try to figure out what is making the screeching sound coming from my serpentine belts/pulleys. I am thinking it may be a bad idler pulley bearing. I just want to double check one thing before I go out there tomorrow and start verbally abusing my car. I haven't personally changed the belts yet. Using the following diagram from the FSM, am I supposed to loosen the pulley nut (on the front of the pulley) before I start loosening the adjusting bolt (under the pulley)? Do I loosen the adjusting bolt first (under the pulley) and then loosen the pulley nut (in front of the pulley)? Do I even have to touch the pulley nut (in front of pulley)?

[slickroger]

Loosen the pulley nut first or you risk bending or mis-shaping the hook that the adjustment nut uses to adjust

[Pwnin O'Brien]

So I finally got a chance today to pull off my serpentine belts and idler pulleys to see what has been screeching. Well I pulled the belts of and soaked then scrubbed them with a hot Dawn (dish soap) bath. I pulled off the pulleys to check their functionality and everything seemed ok. I cleaned the pulleys and their respective hardware off and applied some new grease to the sides of the pulleys (around the bearing). I also decided to do the unthinkable, I gave the belts a thorough coating of belt conditioner (the CRC Belt Conditioner in the red can) before re-installing them.

Well once I got everything put back together and re-tensioned the belts I fired up the car to see if the belts were tensioned enough. Well the screeching was completely gone now, but now there was a really loud "whoosh" sound coming from the belt/pulley area, almost as if the fan was pulling a lot more air then usual at idle (even though it wasn't). I am thinking that the noise is the belt conditioner on the belt, making a sticky noise, like peeling tape off of a solid surface.

Has anybody else experienced this before?

I checked and cleaned all of my other pulleys (and the fan clutch) and everything is in perfect working order.

[slickroger]

nice work I have to do this to im screaching like crazy and its driving me nuts. Going to change those Oil cooler O-rings also let me know when you confirm your whoosh sound so i dont go crazy trying to figure out what it is.

[Pwnin O'Brien]

So I made a quick little audio clip of the noise coming from the front of my engine. The audio quality is a bit low since it was taken on my iPhone. The noise can be more described as a high pitched sucking noise, kinda like the sound from the hose on a vacuum cleaner. This was recorded right after a cold start, the hood was closed and the phone was held at the front grille and swept from side-to-side.

My YouTube Video of This Strange Sound

[slickroger]

Thats a sick vid but I dont know what the sound is sorry.

Im going to do the same thing you did tomorrow so ill let you know if i get a similar sound

[K03sport]

why did you put the belt conditioner on there?

more than likely, the squealing was coming from the pulleys. If your belts showed ant signs of cracking, i would replace them.

as far as the sound...no clue. It could be due to the extra tackiness of the conditioned belts

[Pwnin O'Brien]

Well after a little research, I found that the sound is perfectly normal. I read on a couple of forums that it is the belt sticking to the pulleys. I also read on an RSX forum that the CRC belt conditioner works really well. This guy did a dyno pull before and after (of course, he has a supercharger or something of the sort) to show how much slipping his belts were getting before he applied the conditioner.

This is a good read if you're using the CRC stuff... http://forums.clubrsx.com/showthread.php?t=369967

[Pwnin O'Brien]

why did you put the belt conditioner on there?

more than likely, the squealing was coming from the pulleys. If your belts showed ant signs of cracking, i would replace them.

as far as the sound...no clue. It could be due to the extra tackiness of the conditioned belts

The belts are fairly new, that's why I was so confused as to why I was getting squealing. The belts were also tensioned perfectly before I took them off. I applied the belt conditioner so I could guarantee no belt slippage; this way if there was squealing after I put everything back together I would know it was the pulleys. Needless to say, there was no more squealing after I put the belts back on.

[alexf20c]

squealing from the pulleys has nothing to do with belt quality. if it's the bearings that are going bad, applying belt conditioner won't do you any good.

if the squealing noise is caused by belt slippage, then yes, belt conditioner will help.

the squealing you heard was probably the belt slipping. the idler pulley bearings are not regreasable so all you did was apply grease to the retaining caps, which actually see no movement. if the pulley bearings are shot, they must be replaced, and can not be regreased.

[Pwnin O'Brien]

squealing from the pulleys has nothing to do with belt quality. if it's the bearings that are going bad, applying belt conditioner won't do you any good.

if the squealing noise is caused by belt slippage, then yes, belt conditioner will help.

the squealing you heard was probably the belt slipping. the idler pulley bearings are not regreasable so all you did was apply grease to the retaining caps, which actually see no movement. if the pulley bearings are shot, they must be replaced, and can not be regreased.

With the belts on the vehicle, I was unable to tell what was actually squealing. By removing the belts and cleaning the belts and applying the conditioner I was able to rule out the belts being the problem. Luckily the squealing was gone after I put everything back on and it still hasn't come back.

I applied new grease around the bearing seals to prevent bearing contamination. The new grease will act as a seal to block moisture and dirt. Also, it looked as though the pulleys had come from the factory with grease around the seals.
Modified by Pwnin O'Brien at 11:54 AM 11/3/2009

[Densetsu]

If the noise comes back and you still can't pinpoint it, a mechanic's stethoscope is a great tool to have. They're usually pretty cheap too, maybe $10 or so. Just be careful around moving parts, like the belts. Mine also came with a horn attachment, which let me isolate the noise without having to directly touch the engine with the probe.

http://www.amazon.com/KD-TOOL-...6TYR2

[slickroger]

I did exactly what you did Pwnin I conditioned the belts and lubed up my tensioners and the ridiculously unattractive loud pitched squealing is gone I don't know how long it will last but I will keep you posted. Mine are brand new belts but i do suspect slippage as the problem simply because my pulleys arent making any sounds out of the ordinary. Keep me posted on your loud belts if the sound comes back

[GRNMACHINE]

Will definitely give this a try. The noise is driving me crazy.

[GRNMACHINE]

Spent a little too much time trying to get rid of the squeal. Belt conditioner didnt help. It started to make a really weird sound 4 days ago. Thought maybe it was a vaccuum leak so I took off the Spectre Intake I put together and the Jim Wolf Pop Charger and installed all the original parts. No change. Broke down and took it to the dealer today. Crankshaft Pulley (Harmonic Balancer) was toast. I am broke now but the Pathfinder is driving like new. Dealer was fantastic as well.

[gatorpits21]

I can only find 2 belts yet autozone and others says there is 3 belts on my 2001 nissan pathfinder 3.5L

[alexf20c]

have you checked under the hood and counted?

[2 Coupes]

Autozone is correct there should be 2 belts. The only other belt that they may be talking about is the timing belt (not applicable to you) your pathy has a timing chain (No replacement needed). Only <2000.5 pathy/QX4 have timing belts.

[Chuck Tribolet]

Autozone is correct there should be 2 belts. The only other belt that they may be talking about is the timing belt (not applicable to you) your pathy has a timing chain (No replacement needed). Only <2000.5 pathy/QX4 have timing belts.

He said Autozone said THREE belts. Autozone is wrong, not correct. My '01 has two belts and no place to put a third. I think my '72 240Z and '70 pickup
had three, with the third driving the smog pump.

I'm not sure I'd call them serpentine belts. My '87 'vette has one belt and THAT'S serpentine fer sure.

[Benster]

My son has a 2002 Pathfinder LE and the Nissan shop says his A/C belt is cracked and needs to be replaced. Is this the serpentine belt or is this the "other" belt? My son is broke. If this failed would it merely stop the A/C compressor from working or would there be other issues? We have had issues with after market serpentine belts but I'm wondering if the A/C belt is a more common, (less complicated ) belt and I could have Firestone replace it?

Thanks

[greengumby]

depends on how bad the cracks are ..if they are not too worn you may be able to stretch the useage a little ...
firestone locations like to replace things ahead of time i noticed when i used to go there .. i found this out when they tried to charge me an extra 35 bucks to swap my tires cause i had tps sensors in them . You would lose the AC if the belt snaps but its not a show stopper verses losing the main belt thats a bad issue to experience.

[Buzzman]

Losing your serpentine belt will mean losing your alternator and power steering. Not a good thing.
If there's any doubt about it's longevity, then I'd replace it. It's a DIY job.
Word of wisdom: these belts need to be on there as tight as possible, or else they'll squeal like a drowning rat.