SOLVED! Rattling/knocking sound (video)

[masaidwakeup]

Hey everyone,
I need some help diagnosing an issue that just started today.
There's a strange knocking or rattling noise coming from the front of the motor (I think).
The noise is intermittent and doesn't seem to be linked to the engine RPM.
No matter the revs, the sound is consistently inconsistent.
Sometimes it's completely gone for a few seconds and then comes back randomly.
At first, I thought maybe be the timing chain guide had broken, but the noise isn't matching the engine RPM.
I'm not sure what's going on.
Any assistance would be greatly appreciated.

Also, is that radiator fan wobbling?

here's a video of the noise

 

[TollKeeper]

From what I can see in that video, I would say your cooling fan clutch has gone bad.

 

[mrrsm]

Just my ...But...

Based upon the *Wobble* in the Outer Orbit of The Fan Shroud evident in the Video that SYNCS with the Sound...The More Likely Culprit is probably that... The Water Pump Bearing(s) have 'Gone Sideways' and the Noise being generated is echoing out from inside of the upper part of the Engine Block...

 

[masaidwakeup]

From what I can see in that video, I would say your cooling fan clutch has gone bad.

Thanks for the input and I think you may be right.
From the additional research I've done and youtube videos I've seen, it seems the fan clutch is on its way out.
I've seen electric fan kits out there.
I've also been looking at upgrading to a high output alternator as well.
Maybe I'll take this as a sign to finally pull the trigger on one of those.

Would you recommend swapping to an electric fan?

 

[masaidwakeup]

Just my ...But...

Based upon the *Wobble* in the Outer Orbit of The Fan Shroud...The More Likely Culprit.. is probably... The Water Pump Bearing(s) have 'Gone Sideways' and the Noise is echoing out from inside of the upper part of the Engine Block...

Interesting.
Would simply replacing the water pump resolve that issue?
To be honest, that's probably due for replacement as well.
I'm very far the first owner of this truck and have no idea when it was last replaced, if ever.
Thanks!

 

[mrrsm]

The way to Test The Possibility...is to Temporarily ... Remove the Serpentine Belt and then Run The Engine at Idle for just a few minutes...if the sound subsides... "Bob's Your Uncle...and Fanny's your Aunt..." :>)

Also...with the Belt OFF... GENTLY... *Wobble* the Fan Shroud Fore & Aft at the Outer Edge of its Orbit just a bit... Looking for Excessive PLAY in the WP Bearings... and maybe... hold off on performing the Electro-Viscous Fan Clutch R&R, etc. for 'Half-a-Tick'... Just until you can make this other determination. :>)

 

[Mooseman]

Would you recommend swapping to an electric fan?

NO! Been there, done that, drank the Kool-aid. Poor cooling and A/C performance is the result. The radiator is just too small to be able to effectively cool, which is why the engineers went with the mechanical fan to compensate. I'd go with a thermal version from a 2008 and have the fan codes turned off with a tune.

 

[masaidwakeup]

Update:
The issue was either the water pump or the fan clutch.
Since both were due for replacement, I decided to swap them out without troubleshooting them independently.
The issue is now fully resolved.
My guess is it was the water pump—the bearing was rattling around the housing like a ball bearing in a spray paint can.
Radiator fan wobble is also completely gone.
I appreciate all the help and advice.

Thanks, everyone!