Knocking coming from engine

Hey guys, this problem is driving me nuts. Could really use some help of figuring out what the problem is.

A few days ago I start noticing knocking coming from the engine, at idle, after a cold start and would fade away when the engine warmed up.

Sounded like this (fast clicking because of a higher idle during cold start):




Today, after driving around 40 miles round trip to the courthouse (thanks, Jury Duty), the knocking occurs even on a hot engine, and seems to have doubled up, like this:



Anyone have this happen to them, or knows what's going on? Part of me thinks it's a rod, but the rest of me says no, cause that would be a large PITA.
It's driving me nuts because it happens everytime I drive which reminds me constantly of the problem, like a nagging SO.

Thanks in advance, guys.

 

Mobil1 5W-30 changed just a few weeks ago, and ever since I've got the truck I've run 91 octane fuel through it.

 

Last August, a DIY job with NGK Iridiums.

 

Unlikely. I believe that's a piece of electrical tape.

 

Yeah, I thought it looked like that too but it turns out it was just flapping around with the engine fan pushing air around. I cut it off and the same noise still occurs.

Small update; cold started the truck this AM and the sound is back to tempo of the first video: single knocking. I'm sure if I drive it around for a while and let the engine get to operating temp it'll go back to the double knocking in the second vid..

 

That sounds like a nightmare.

The sound does seem to be coming from the driver's side...although the vid on the first page of that thread is way different than mine: screeching vs. knocking.

 

If oil pump is failing that's easy to check. Harbor freight sells cheap oil pressure testers.
In Full warm up engine there should be atleast 4 psi at idle and around 80 psi at 3000 RPM or so.
Check that first, to rule out oil pump going bad good luck and keep us posted.

 

I just had a chance to watch video (could not at work) but that does not sound like rod knock. It sounds like its half of the RPMS of engine. I would check engine mount to see if it is not broken and if you are not hitting shroud. Check your PS fluid as well.
BTW that would explain the change when engine gets hot, fan clutch engages more with temperature

 

Well, it appears that the problem has been solved..

Looks like when I replaced the serp belt I missed ONE (1) groove on a pulley. I took a good hard look at how the belt was seated and noticed it looked off track on a pulley. I took the tension out of the belt, seated the belt correctly, started the engine, and no more knocking.

Thanks to the guys who pointed me that direction. I feel like derp right now, screwing up something as simple as that. Though I'm not sure why it didn't manifest itself right away.

Really glad it wasn't as severe as an oil pump going out (yet...)

 

Dont feel like derp. Anybody who worked on cars atleast once had that moment