Help - high pitch whistle/squeal after BF idler

[03CobraVertGrey]

I just installed a new BF interchangeable pulley (2.93) and the new style snub idler (100mm). I had a professional remove and reinstall the pulley and put on a Gates belt per the Billetflow recommendation.

Now there is a high pitch whirring sound (hard to describe) coming from the blower snout pulley area and I think it is the belt due to the extreme belt wrap with the new style idler (we had to manually roll the pulley to get the belt to slide in between the idler and the pulley during install). I thought at first it was caused by too tight a belt since the sound got quiet or stopped when I put the ratchet in the tensioner and took the tension off while the engine was running. So, I changed from a 74.5 to a 75 and then to a 75.5. That didn't help.

I did a few searches and could find nothing on this. The sound is even more pronounced now that i have removed my hood blanket. It almost sounds like I have gear drive. :dw:

Anybody know what is going on here?:??:

 

[dougwg]

"(we had to manually roll the pulley to get the belt to slide in between the idler and the pulley during install)"

Sorry but this is not the way to install a belt....

Exerting that much force on the bearing of the idler could have damaged the bearing which could cause a "whirring" sound.

Without having the car right here in front of me it just about impossible to diagnose the issue.

 

[dougwg]

http://www.svtperformance.com/forums/showpost.php?p=3462337&postcount=11

 

[03CobraVertGrey]

"(we had to manually roll the pulley to get the belt to slide in between the idler and the pulley during install)"

Sorry but this is not the way to install a belt....

Exerting that much force on the bearing of the idler could have damaged the bearing which could cause a "whirring" sound.

Without having the car right here in front of me it just about impossible to diagnose the issue.

Doug, I think you misunderstood. In order to fit the belt in between the 2.93 and the 100mm idler, you have to roll the pulley with your hand while sliding the belt in between it and the idler. This was not a forced issue that would cause any damage to any bearing nor the belt, I was just making the point that the clearance b/t the pulley and idler is very close and hence my opinion that the noise is coming from the belt due to the extreme wrap and therefore causing a vibration of the belt itself. Hope that makes better sense. So, you have never heard of this? Would it be helpful to see/hear a video of this since you can't see it for yourself?

Edit: I have looked at your post and I see that you did it another way but no force was put on the idler/pulley that would affect the integrity of the bearings.

 

[JB]

many of us have extreme wrap with no problems or noise :shrug:

 

[TriPodRacing]

You should wrap the belt around all the pulleys except the idler closes to the tensioner. Then pull up on the tensioner and slide the belt over the idler.

I think every Cobra with a smaller upper makes a little whistleing noise. At least the ones I have heard.

 

[JB]

You should wrap the belt around all the pulleys except the idler closes to the tensioner. Then pull up on the tensioner and slide the belt over the idler.

did you read the link that Doug posted?

the method of installing snub idler last is the easiest way and doesn't stress the belt or bearings

it is also the only way to get on an extremely tight belt...

 

[Hicompression]

Does Gates make the Gatorback belt? I can't remember if its Gates or Goodyear... Anyways, if you are running a Gatorbback belt it makes a hell of a whistle/whirring sound because of the crosscut v-ribs.

 

[JB]

Does Gates make the Gatorback belt? I can't remember if its Gates or Goodyear... Anyways, if you are running a Gatorbback belt it makes a hell of a whistle/whirring sound because of the crosscut v-ribs.

good point....GY Gatorback does make a lot of noise

 

[TriPodRacing]

did you even read the link that Doug posted? :dw:

No

This is how I have put the belt on every Cobra that I have installed a belt on.

Maybe I didn't explain it enough.


Put the belt behind the tensioner first. Then route the belt around the crank pulley,then the lower idler,next around the alt. up around the idler and snubber pulley and around the blower pulley. Then take the tension off the tensioner and slip the belt over the last idler.


Is that better.

 

[JB]

No

This is how I have put the belt on every Cobra that I have installed a belt on.

Maybe I didn't explain it enough.


Put the belt behind the tensioner first. Then route the belt around the crank pulley,then the lower idler,next around the alt. up around the idler and snubber pulley and around the blower pulley. Then take the tension off the tensioner and slip the belt over the last idler.


Is that better.

your way will work, but it can be hard on the belt.....I'm just saying that the method Doug described is a better way to do it, especially with the new-design BF snub bracket, which has very little clearance when installed


"install the last 100mm BilletFlow idler pulley onto the Snub Idler Bracket (actuate the belt tensioner with your left hand, cup the pulley in your right hand and push the beltover using the pulley till you can slide the pulley onto the boss of the Snub Idler bracket)

then install bolt into the Snub Idler Bracket that holds the pulley on"


BTW, I edited my previous post to explain myself better and not be such a smartass :beer:

 

[Dana]

It is probably just the air being forced through the crosscut grooves on the new pulley.
If there was belt damage during the install, you would see it, as the belt would not run true. I don't think this is the case, I think it is just a lot of air having nowhere to go.
Some belts, like the Gatorback, seem to make more noise than others. Drive it for a while and see if it calms down some.
If you are still concerned, loosen the belt and spin the idlers and alternator by hand to check for issues. Again, I don't think that will show anything though.

Dana

 

[utfan98]

or maybe he has a 12-71 blower.....

 

[CobraBob]

Sometimes our mind exaggerates the noise we hear. Making it worse than it really is. If your whine is as loud as you describe, it is not likely the belt. Even if it was a Gatorback the noise nowhere comes close to resembling a gear drive. Now if it was an RPM Outlet cog setup, yes. LOL!

Any possibility of posting an audio file of the noise?

 

[427Windsorman]

I have the same whirring sound, but so far, no problems. I think it is just the belt on mine.......

 

[image]

Ditto.. I have a whining sound... Don't worry its fine.

 

[BlueSS]

My upper 100mm idler has the grease/lubricant coming out of it? Does anyone else have this?

 

[03MUSCLE]

Mine Does It Also Then Goes Away.

 

[image]

Mine get's alot of dirt inside of the iders. I guess that's due to me having to park my car outside with functional hood scoopes. It sucks too because when it rains (humidity in houston doesnt help either) my belt squeeks for awhile.

 

[Juruense]

As was said Gatorbacks will make a noise like a blower even on n/a cars.