Blower belt idler pulleys - are yours squealing?

[fullboogie]

Like some of you, my car developed a squealing pig under the hood that was growing worse. I isolated it to one of the pulleys on the blower belt. If you've ever tried to ID the three pulleys (not counting the tensioner pulley) through online parts diagrams or listings, it's a real pain in the ass because the part numbers have either changed, or they are only listed by the first four or five digits, not the complete part number. Trying to cross reference those on parts websites was futile.

Willie (fellow forum member) was kind enough to send me his spare pulleys to help diagnose which one on my car was the problem. Using his (and my OEM) pulleys, here's what you will need. I figured someone down the road will need this:

Pulley Number 1 is the idler that many of us replace right off the bat when we go with a smaller blower snout pulley. Commonly available from everywhere.

Pulley Number 2 is the grooved pulley, OEM part number 4G7V-6C348-AA.

Pulley Number 3 is a smooth pulley, also referred to as the "high tension pulley" online, OEM part number 7R3V-19A216-BB.

The lower left corner is the A/C pulley, and the tensioner pulley is obvious down and just to the left of Pulley No. 3.

For what it's worth, I just bought all three pulleys, and a replacement pulley for my Thump tensioner, in lightweight version from BPS for a whole lot less than I could find the OEM ones online. Hope this helps someone.

 

[Catmonkey]

Could you figure out which one was the problem?

 

[CobraBob]

Glad you solved your problem. That is helpful info you provided.

So, but did you pinpoint it to a specific pulley?

 

[fullboogie]

Cat and Bob:

No, I can't figure out which one is giving me the problem because spinning them by hand, moving them back and forth, just doesn't give me any clue as to which one is the culprit. So rather than changing them one by one, with the belt removal and reinstallation for each one, I'm swapping all of them out for BPS lightweight units including the pulley on the Thump tensioner.

I know this isn't an exciting subject, but it's been very frustrating trying to track down part numbers. I thought I'd save someone a little time by posting this. By the way, that's not my engine. I pulled that pic from Google.

Side note - I'm surprised that I have a pulley going out at 10k miles. Silvain at BPS suggested that the higher tension from the Thump unit may cause rapid wear on the various idler pulleys on the blower belt. Keep that in mind.

 

[HillbillyHotRod]

Have you tried a stethoscope?

 

[fullboogie]

Not even going to try it. Getting past two spinning belts deep into the engine compartment does not make me comfortable. Replacing all of them is the best course of action, since at least one is bad and more may go bad soon.

 

[mysticsvt]

Are those stock idlers? If so get rid of that junk asap! My lower left me stranded when the metal sheared back cut the belt and nicked my 4lb lower. I say Metco, no BilletFlo if either are still around. -Shane

 

[69b302]

Lots of times the belt squeak is due to aftermarket blower pulleys not having proper alignment.

 

[jenkins_1120]

I went through this last year. Ended up being a bad idler pulley and something on the belt. I tossed the gates blue belt for a stock belt. it doesn't squeal anymore but it has slipped some when the belt gets hot

 

[Catmonkey]

They usually have to be pretty bad off to figure out which one is squealing. I agree, time is money and the pulleys are not that expensive. I think a lot of people are running more tension as a result of upper and lower pulley changes, aftermarket tensioners and auxiliary pulleys. If you have trouble getting your belt back on, you're probably a candidate for a bigger belt.

 

[moncho]

BPS seems to be a good resource for these types of items. Thanks for the heads up & good luck!

Cheers

 

[merkyworks]

Just curious on lightweight pulleys Vs OEM pulleys.

Besides just being lighter do lightweight pulleys rob less power/let the blower spin up more easily?

 

[fullboogie]

I cannot imagine them having any measurable effect on the HP. I'm using them because they're a good bit less expensive compared to OEM and they use the factory style Nichi (sp?) bearings.

 

[SCGallo2]

Yes, squealing like a stuck pig after cold start up. As my engine warms up to operating temp, squealing decreases and completely stops. Probably going to work on it this weekend, and I have a good idea on where to start because I remember what I changed prior to hearing the squeal for the first time. I'll report back with what I find...

 

[fullboogie]

Mine started the same way - chirping and squealing on startup that went away after it warmed up. It rapidly went downhill to the point that I could not drive it. Good luck man.

 

[GT Premi]

...
For what it's worth, I just bought all three pulleys, and a replacement pulley for my Thump tensioner, in lightweight version from BPS for a whole lot less than I could find the OEM ones online. Hope this helps someone.

I hope you didn't opt for the "upgraded" ceramic bearings. They're noisy. I replaced my stock pulleys with BPS billet pulleys and opted for upgraded bearings. Love the pulleys. Don't like the noise.

Just curious on lightweight pulleys Vs OEM pulleys.

Besides just being lighter do lightweight pulleys rob less power/let the blower spin up more easily?

I cannot imagine them having any measurable effect on the HP. ...

It depends on what else you've done to your power train. In my case, yes, they definitely make a noticeable difference in how quickly the engine spools up. They also make a difference in how quickly the engine stops spinning when I turn it off. I have over 20 lbs of rotating mass off just my engine, though. The lightweight pulleys seemed to be that little bit more that pushed it over the edge to make it more noticeable on just the engine, i.e. revving it with no load. I have around 100 lbs less rotating mass on just the drive train; billet pulleys, lightweight clutch assembly, CF driveshaft, lightweight rear brake rotors, lightweight rear wheels. I have over 100 lbs total less rotating mass.

 

[fullboogie]

I hope you didn't opt for the "upgraded" ceramic bearings. They're noisy. I replaced my stock pulleys with BPS billet pulleys and opted for upgraded bearings. Love the pulleys. Don't like the noise.

I wasn't even aware of the option to upgrade, so I'm thinking that's not what I'll get. Thanks for the opinion on the BPS pulleys - I hope they work out.

 

[fullboogie]

Update for posterity - here are the torque values for when you replace the pulleys:

Pulley No. 1 - 18 lb ft

Pulley No. 2 - 18 lb ft

Pulley No. 3 - 35 lb ft

Tensioner to timing cover - 35 lb ft

Tensioner pulley - nothing in the diagram, so I'm going with 18 lb ft.

These values are per the service manual diagram below. You can also see in the chart at the bottom the lack of full part numbers. Also note that numbers 5 and 9 below are both listed as "19A216" but in fact, they each have different prefix numbers and suffix numbers. That's what was so confusing to me.

 

[moncho]

Great info. Will bookmark for future reference.

Thanks!

 

[fullboogie]

Update - the new BPS pulleys cured the chirping/squealing. *Crossing fingers.*