Bit of a head scratcher this one. I bought a 2014 Titanium X Sport (manual) with 7.5k on the clock about 5 months ago. It's now done nearly 20k.

On Saturday morning and again yesterday afternoon I noticed a strange knocking sound inside the car. At first I thought it was someone hammering in the street, but when I turned the engine off the noise went away and came back when I started the car up again. I opened the bonnet and could not hear the noise. I went round the back to where the exhaust is and still could not hear the sound, but when I got back in the car it was clear as day! I tried to figure this out for a few minutes and the noise then mysteriously stopped.

As stated, it came back again yesterday whilst I was sat at traffic lights. I killed the engine and started it up again a couple of times but the noise would not go away. I revved the engine slightly and the noise got quicker (and possibly quieter) as the revs increased. The lights changed so I continued until it was safe to stop, by which point the noise had again mysteriously stopped.

The garage are saying that they will be unable to do anything unless the noise is manifesting itself, so I am at a loss as to what to do or what it could be!

Does anyone have any ideas? If there is a potential problem that needs attention I would rather get it addressed before the warranty expires!

Many thanks in advance!