86 6.9 tapping noise

[steelheadguy]

Well I started my truck this morning and it sounded normal. Then I had to run back inside for 10 minutes, when I came back outside there was a tapping or flapping noise. I popped the hood and it looked like a belt was loose, I tightened it but the noise hasnt stopped and I dont think it is the belt anymore. I just did an oil change and the oil level is fine. It almost sounds like a baseball card in bicycle spokes. If I give it throttle the sound revs also. I checked for anything in the way.

It sounds like the noise is coming from near the alternator or waterpump area but I cant pinpoint it. Any insight on where I should start or what this could be?

 

[steelheadguy]

I read about how it could be stuck injector and I should loosen each injector one at a time. To do this am I loosening the injector or the nut that holds the line to the injector?

Also I noticed when I just started it, there is no noise for maybe 10 seconds. The noise somewhat resembles a slow train going over the tracks or a skateboard on a sidewalk.

 

[crash-harris]

Loosen the line from the injector, not the injector itself.

Was the truck sitting on an incline when it first started making the noise?

 

[steelheadguy]

OK I loosened the injectors til the engine slowed a bit and it had no effect on the noise.

The noise seems to be coming from near the fan more than the engine. Im trying to upload a video of the noise.

 

[steelheadguy]

No it is not on an incline

 

[crash-harris]

Coming from the fan? Sounds like a playing card in bicycle spokes?

Are you sure there isn't anything sticking out and hitting the fan blades? Maybe something hanging that the fan is pulling towards it when running? Video will help. You can upload your video to youtube or photobucket and just link it in your post.

 

[steelheadguy]

I know someone is going to say it is supposed to sound like that, but the fact is, it didnt sound like that yesterday.

https://youtu.be/itgsJ8kfrbc

 

[steelheadguy]

Coming from the fan? Sounds like a playing card in bicycle spokes?

Are you sure there isn't anything sticking out and hitting the fan blades? Maybe something hanging that the fan is pulling towards it when running? Video will help. You can upload your video to youtube or photobucket and just link it in your post.

Ive been looking everywhere for something hitting. But I cant find anything.

 

[steelheadguy]

Wow. All day I was afraid to drive the truck or even rev the engine. I drove about a mile and now the noise is gone.....

If I didnt just record the noise, I would think Im going crazy.

Still... Any ideas? When it was making the noise, Id start the truck, in about 10 seconds I would hear one tick, then two, then more slowly building up to a constant revolving tick or tap.

 

[larson]

You sure it's not that belt flopping around? Looks pretty damn loose to me. Make sure it's not hitting anything. Can you start the truck for a few minutes with that loose belt removed to see if that's the noise?

 

[steelheadguy]

Well now the noise is not there so I cant troubleshoot that belt. but if it comes I guess I could try. Will the truck run fine without the alternator spinning? and what is connected to the alternator? the vacuum pump? will it run without both of this spinning?

 

[BrianX128]

Maybe I'm nuts but I can almost swear the noise is timing up perfectly with the belt smacking something under your alternator there. It's like too synced up for that to not be it.

 

[79jasper]

Gotta be the belt.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[icanfixall]

Sounds to me like a bearing is failing on one of the accessories on the front of the engine. But p-lease look closely at what the belt might be rubbing on. Those alternator belts do flop around a lot. Sadly the alternator belt is the last belt to come off the engine but the first belt installed. So start removing the belts one at a time and run the engine till you find the possible offending belt or bearing. Its easy to listen to each bearing with a stethoscope or a long screwdriver pressed against the housing to the suspect bearing.

 

[crash-harris]

Definitely replace that belt if it won't tension anymore.

But what in the hell is it routed around that's under the vacuum pump?