I’m experiencing a loud annoying noise when accelerating. It resembles spark knock and or a heat shield rattling. If I accelerate slowly or romp on the gas it may not occur. If I let off the gas it stops. One mechanic was able to mimic the noise by holding the break and revving the engine to approximately 1800 rpm but he wasn’t sure what it could be, he also checked all heat shields he could find. Also if it’s really cold it doesn’t usually do it until the engine is at full operating temperature. Motor mounts were recently replaced. If nothing else the sound is very annoying.
So as usual I was on YouTube and another Nissan owner suggested it was the intake manifold power valve.