Re: VM Motori Engine Harmonic Noise
The metal lines are all high pressure. Brakes, A/C, fuel. I don't know what that one is off-hand, but if I were you, I'd trace it to both ends and determine what parts it feeds from/to. Usually, harmonic noises in high pressure lines are one of two things: bad pump or bad valve. If you locate the culprit, sometimes cleaning it can restore it to silence.
Deep Cherry Red 2015 JGC Ltd EcoDiesel with Beige Interior / ORA II / Lux II / 8.4AN
Mods: DEF injector guard | Mopar splash guards | Green Hornet fuel cap | Fumoto F-106 oil drain valve | aFe Pro Guard 7 engine air filter | Mopar molded running boards | Mopar roof rack cross bars | Mopar rear cargo net | Mopar rear cargo liner | Husky X-Act Contour floor liners | Mopar "Rugged Off-Road" Black & Machined 18x8 wheels