Intermittent knocking noise
I wonder if anyone could help me, I have a Alfa GT 2.0JTS which i absolutely love but its got an intermittent knocking noise like there's something in the tyre but its fine. It is loudest when the cars cruising along with no pedals being pressed but as soon as i press the clutch pedal it disappears. I've had it in 2 garages so far and neither of them could get the noise to happen which is annoying but based on my description they have said it could be gearbox but couldn't be sure unless they stripped it.
I would like to avoid the cost of a gearbox strip if its just a bearing or loose bolt somewhere so if anyone has had a similar experience could you help me please.