Hi All, my 4.4 l405 has developed this really annoying ’tizzing’ noise from underneath. I’m sure it’s nothing serious, and I’m pretty sure it’s not the exhaust. I’m guessing it’s a heat shield of some sort. It only happens at a specific vibration frequency around 1100rpm..

Has anyone else had similar, and if so, any ideas of the location and fix…?

Thanks..

There is a heat shield around the gearbox area which can resonate really loudly. Mine does it too but slightly higher rpm.

I’ve looked underneath and can feel it’s loose and replicate the sound … so I’ll need to replace it at some point V8 or else ...

Seems it’s the dpf…, or something around the dpf….