Huh, guess I missed that video but I'm not sure if it's just the recording but mine sounds different. Ill take a video in the morning to compare the two.

 

right on top on the passengers side of the engine front there is a bunch of hoses hooked to a Diverter valve with a wire plug and a vacuum line...you can try unhooking the vacuum and see if the diverter switches...

On my truck it goes one way cold and then another hot... I can just unplug the CTS (2-wire Coolant temp sensor) and the diverter will switch.... you can try that as well...

The thing about about removing the belt I am not sure that would work but totally worth a shot... cant really say the AIR pump isnt shot and the noise is coming from that and multiplying through the bracket to the engine so its worth a shot...

What happens when you do this...? start it up cold and when it starts knocking shut it off wait a few minutes and restart it... does it knock right a way or do the same thing again?

With the AIR the diverter gets its info from the CTS... when it switches it goes from the pipes in the back of the heads (with Check-valves) to the pipe in the exhaust...

sounds to me like there is a point in time where one of the check valves might have a rust hole in it and the knock you hear is when its trying to open....

thats my train of thought but then again it could totally be something else...

 

well the CTS is easy enough to unplug and plug in.... if this could effect where when the exhaust goes to/through the tubes, how should this work? if it is making the knocking sound, unplugging this might make it stop? Its early so the brain isnt up so speed yet so I apologize.. I guess I am asking is when or what should make the knocking start/stop in trying these things. (if that even made sense).

 

well my thought is ruling out different things... the valve is in one direction cold and another when its warm... unplugging the CTS and switching the valve will tell you something if it works... if nothing happens no harm no foul....

 

So by doing this I should be able to start and stop the noise IF it is the check valve, or tubes? IF the valve is working properly?

 

thats what we are trying to rule out

 

Where exactly is this valve? On top of the intake or front of engine somewhere? Also...as a side note when I turn the truck off.. I can hear what As best as I can describe, like a air leak for maybe 5 seconds...normal? Perhaps all this could be caused by a bad vacuum line?

 

not normal.....

there you go

 

Guess I don't exactly know what the diverter valve looks like.

 

I started her up tonight, strange thing is it didnt seem to make maybe half the noise that it was making.. weird.. anyway, I unplugged the coolant sensor...I couldnt hear anything different anywhere, and it didnt seem to make any difference. I tried this right after starting, and also after it warmed up. The air noise I thought I was hearing after shutting off, I dont believe that is anything. Didnt do it tonight, may have been the a/c or something. Exactly where is this diverter valve? I dont see what you describe at the front of the engine.. what is it close to? happen to have a picture? I just dont know what it is.