Strange noise

[TR Custom Parts]

trying to diagnose a noise on a friend's car, not anywhere near him and only have a video. Take a listen

How do I post a video

 

[John Larkin]

Post it on youtube and then imbed the video here.

 

[TR Custom Parts]

https://www.youtube.com/embed/n_JX6msrSPQ

 

[V6sleeper]

Idler pulley bearing?

 

[626gn]

Idler pulley bearing?

Good guess. Or possibly tensioner? I had a noise similar but not as severe. When I put a stethoscope on my alternator case it sounded exactly like that only with the naked ear it was much quieter than your video. Have you tried removing the belt to narrow it down to somewhere in the pulley system?

 

[Daniel PErkins]

I would shoot for either the tensioner is shot--bearing has failed or the alternator front or rear bearing has failed. Disconnect belt and start spinning all the stuff that the belt touches. The a/c compressor clutch could be a culprit also. See previous sentence. Dp

 

[deezdad]

I don't know crap but you can see in the vid something moving along with the noise right next to the maf.

 

[626gn]

I don't know crap but you can see in the vid something moving along with the noise right next to the maf.

Good eye

 

[John Larkin]

Something is jumping under those green wires. It looks like the cam sensor.

 

[TR Custom Parts]

He did put a new belt on it so maybe it is too long and tensioner is bouncing? He has a new billet tensioner on it so that would rule out the pulley bearing on that. Really need the car in front of me getting frustrating trying to text him this info, not Buick savvy at all!

 

[Pronto]

The cam sensor is bouncing around making that noise. Loose hold down bolt? How's the oil pressure? Maybe the oil pump is jamming and shaking the cam sensor?

 

[mikestertwo]

My vote is something with the belt tensioner. I don't think it's the cam sensor since I don't see the cap moving just the wires. I don't know if it's my imagination but it also looks like the alternator is jumping when the noise occurs. I would check both the belt tensioner and the alternator.

 

[626gn]

He did put a new belt on it so maybe it is too long and tensioner is bouncing? He has a new billet tensioner on it so that would rule out the pulley bearing on that. Really need the car in front of me getting frustrating trying to text him this info, not Buick savvy at all!

Given this info I'd definitely verify what belt length was used.

 

[TurboDave]

The cam sensor is bouncing around making that noise. Loose hold down bolt? How's the oil pressure? Maybe the oil pump is jamming and shaking the cam sensor?

I don't think so..... Watch the alternator real close, you can see it "jerking" with each noise pulse. Likely something with the belt or tensioner.

 

[Pronto]

Maybe the bracket is cracked?

 

[TR Custom Parts]

He's running a 64" belt, think the correct one is 63.5". To make matters worse the starter is taking a shit. Tries to crank and then freewheels. Cam sensor is tight so we can take that out of the equation.

 

[Pronto]

Of course just because the tensioner is new doesn't mean that it can't be the cause. Been burned thinking like that before.

 

[V6sleeper]

Step down a belt size.

 

[626gn]

He's running a 64" belt, think the correct one is 63.5". To make matters worse the starter is taking a shit. Tries to crank and then freewheels. Cam sensor is tight so we can take that out of the equation.

Correct. 64" rarely works.

 

[TT/Ameasap]

That is the cam sensor jumping. Better pull that and verify before anymore run time.