2014 Mazda 6 Sport Nav, Clicking to the speed of the car
 

Hi. Im having real trouble trying to locate a knock/clicking noise when i drive. Has anyone else had this issue. Symptoms are You can hear it with windows up not down
If car isnt used for a day the the noise goes for about a mile
It makes the noise in sync with the speed of the car
No noise on idle
No change in performance
Still happens in neutral
No noise when stationary
Oil seems ok but needs a Full service
Checked CV boots
Full lock no noise.
mechanic has had it on the ramps but cant see anythin. Has anyone else had this issue?
any help would be really appreciated

Stones in the tyre tread?

Ok so the car does it when moving in neutral which rules out half the gearbox. has nothing to do with engine revs so rules out the engine. Has got to be something from the tyres to the output shafts of the gearbox then doesnt it?Also has to be something which a mechanic cant spot on the ramp so that rules out most things which wear like cvs, balljoints, bushes, brake discs, pads, Cant hear it outside the car but can hear it inside the car. To be honest, I would ask your mechanic to check the actual cv joints, not just the boots because he appears to have missed something.

I had similar (or same) problem. Car would idle and engine would rev without any noise. No noise when going slowly backwards. But rattling noise (sounded kind of like rocks) with forward acceleration at very slow speeds. Seemed to be coming from mid rear half of the car.

I spent a very long time researching this and came to the conclusion that it was a loose heat shield near the fuel tank. Then I went out there and moved it with an end of a broom and it was very loose. Turns out the rivet used to secure these are known to fail frequently. Ultimately that was the fix.