Tensioner Issue, confused

[07 Boss]

OK, chirping up front and replaced idler pulleys. Still chirping like a bunch of crickets. Changed ThumpRacing tensioner to the stock one that came with my new front cover. Whoohoo, chirping went away. Replaced the pulley on the ThumpRacing tensioner with a 76mm Metco pulley and put the arm back on. Started chirping again.

I can feel the bearing on the pulley I took off the ThumpRacing tensioner and it definitely feels rough/gritty as it spins so I thought I was on the right track with the new pulley. But still chirping.

What else could it be? It is at idle so the arm is not moving or pivoting at all, at least that I can see. What else can be making the noise? I was going to get a new 76 mm pulley from ThumpRacing but I'm a little apprehensive that it won't fix it due the the new Metco pulley still chirping. Don't want to buy a whole new arm if it can be avoided.

 

[BruceH]

Still have the stock alternator pulley? When I had an 8 rib setup the non-bearing 8 rib pulley would chirp a little due to the momentum of the alternator. The stock pulley has a one way bearing to eliminate the chirp.

 

[Wes06]

Hmm
I also noticed a chirp now that I have my DOB hotrod 200amp alternator. Has a regular pulley so is probably that

 

[07 Boss]

New 2010 alternator.

It's not the alternator. It isn't really chirping between shifts or throttle changes. It is squeaking like when the idler pulley bearing went bad. I should video it it.

My thing is I narrowed it to the tensioner. But I can't figure out why when I changed the tensioner pulley the sound didn't go away.

 

[groundpounder]

The change in belt tension between the thumper and the stock could be the "cure". Most likely the lower tension of the stock unit is not causing the chirping bearing to load up in such a way as to side load the bearing.

 

[07 Boss]

The change in belt tension between the thumper and the stock could be the "cure". Most likely the lower tension of the stock unit is not causing the chirping bearing to load up in such a way as to side load the bearing.

So you're saying the extra tension on the belt is causing some other bearing/pulley to make noise? That's kinda a reach but makes sense.

Here is the thing though, the alternator is new (couple K miles) and all of the idler pulleys except the little Whipple adjustable one are brand new Metco ones. The little adjustable one has been checked out pretty good with no end play and smooth operation. The timing cover is brand new so the little bosses the pulleys sit on should be pretty much perfect. That leaves the SC snout pulley, which it's not, the P/S pump pulley, which is on the opposite side of where the chirp is coming from, or the A/C pulley.

Before exploring the option of changing that pulley or compressor, I'm going to have to explore other thoughts. I think I'm going to get in touch with ThumpRacing and have them send me a new pulley. My thinking is that the Metco pulley I have on there might not be working right for some reason. It fit right on there and bolts up good. But maybe there is some subtle difference that might be the issue. I know for sure the old pulley bearing is shot.


Here is the vid with the Thumper arm and Metco pulley.

https://www.youtube.com/watch?v=Q7QPI-koN-M


Here is ten minutes later with the brand new stock tensioner.

https://www.youtube.com/watch?v=PoDZea7F1g8

 

[Wes06]

Do you have a mechanics stethoscope?
That may help finding it

 

[o2sys]

I have the exact same noise but I'm using the UPR tensioner and stock 8-rib pulley on it.

I can't find the source of my chirps either and I've used my stethoscope numerous times.

It was not my tensioner for sure. The only things I can't test while the car is running is the alternator and a/c pullies with the stethoscope.

 

[Saleen304]

I had a chirping earlier this year and ended up being A/C compressor clutch. Try cycling A/C and see it it changes. I ended up just replacing the A/C clutch, pulley, and coil while I was in there.

 

[BruceH]

Is there any chance that coolant is getting on the belt? That will also cause chirping. Happens every time the water pump starts leaking on my pickup.

 

[travelers]

The clearance between the mount and arm may be to close and it's rubbing as the arm moves. The stock may have more clearance.

 

[Marble]

How old is the belt?

Been racing or shifting really hard?

 

[07 Boss]

Is there any chance that coolant is getting on the belt? That will also cause chirping. Happens every time the water pump starts leaking on my pickup.

Nope

The clearance between the mount and arm may be to close and it's rubbing as the arm moves. The stock may have more clearance.

Plenty of clearance. and you can see in the vid the arm is still

How old is the belt?

Been racing or shifting really hard?

Not that old, and I swapped in my new back up belt when the noise first appeared. Put the old belt back on when it wasn't the issue.

And I drive my car like it's stolen. It shifts hard and I manually shift all the time with the ratchet shifter. Haven't actually gone to the track in a couple of months.


Again, it squeaks with the thumper arm and metco pulley, and it squeaks with the thumper arm and thumper pulley (which I know is bad). It does not squeak with the stock arm and pulley. Logically you would think it is the thump arm that is making the noise but I don't have a clue why?

 

[groundpounder]

I'm not familiar with the thumpr tensioner. Can you try the stock OEM pulley with it?

 

[07 Boss]

Maybe I'll try that. Stock pulley on the thumper arm, see what happens.

 

[o2sys]

What brand belt do you have?

 

[Marble]

Could the thumper tensioner/ mechanism be dirty? Meaning when the tensioner is moving there is some metal to metal contact causing the issue?

I've never heard of this and it might a retarded thought but idk.

 

[07 Boss]

What brand belt do you have?

Gates, I believe. Same brand I've been using for the last 5 years. I tried a new belt to no avail.

Could the thumper tensioner/ mechanism be dirty? Meaning when the tensioner is moving there is some metal to metal contact causing the issue?

I've never heard of this and it might a retarded thought but idk.

Not so retarded, that is the same way that I'm leaning right now. I'm gonna try and move my little adjustment pulley so there is less tension on the belt but I have it set pretty tight to keep it from slipping. I'm pretty sure I will get some slippage but at least I can have the arm in another position to see if that changes anything. We'll see what happens. I'm also going to call Thumper on Monday and see what they think. I was thinking about trying to open up the arm but I'm afraid I will not be able to get it back together again not knowing how the spring is in there if I do.

 

[o2sys]

Have you tried spraying plain water to the belt while it's running? If the noise goes away then it's a misalignment somewhere. Maybe the OEM tensioner has a slightly different offset which works better with the other pulleys.

 

[07 Boss]

Have you tried spraying plain water to the belt while it's running? If the noise goes away then it's a misalignment somewhere. Maybe the OEM tensioner has a slightly different offset which works better with the other pulleys.

First thing I did was check the belt. I used a bar of soap but same same. That was 8 weeks ago when I heard the first chirp. I've had this tensioner on there for years, I don't think it is a design/alignment issue.

It has got to be either the arm itself squeaking as it articulates, or it needs a Thumper pulley on there.