Need help identifying a hose

2002 v6 2wd. This line runs from underneath the truck up through the driver side of engine bay and then back behind the engine. There's a vibration in the line that coincides with a ticking sound coming from the back of the engine. It sounds like air escaping from small hole at like 500 bpm. No visible fluid leaks. It's loud and really annoying.

 

Fuel line from fuel filter and gas tank.

 

Yeah, you'd know it if that line had a leak lol.

You probably have a crack in your exhaust manifold (common) and a worn out steering wheel firewall seal, that allows the sound into your cab.

 

The injectors on these trucks can supposedly be notoriously "clicky" sometimes.

 

I'll dig in to all of this tomorrow. Thanks
Could you also tell me what this is? I replaced radiator and all is well but I'm still loosing a little bit of coolant from this connection that's bolted to the firewall.

 

Heater valve.

 

I recommend buying OEM on this one, don't buy from scAmazon or fleaBay, you'll get generic or an authentic looking counterfeit, happens often. Should cost you around $100-110 depending on which dealership you choose at the Toyota Parts site (each one gives you a different price break):

https://parts.toyota.com/p/Toyota_2...Heater-Control-Valve/63183154/872400C010.html

Part # is 872400C010 (previously 87240-0C010) if you need that for some reason.