184000735 - 70B ROAD TEST FOR NOISE RECOGNITION

Start the engine and, with the vehicle stationary, check that the noise in the front area is not present (cyclical noises are from the power unit).Steer, with the vehicle still stationary, to the left and the right and check that there is no irregular noise.Set off from stationary to check that there is no metallic noise, roughness or transverse vibrations.Road test the vehicle on an unmade road, engaging the various gears, to check that the noise is not from the gearbox, clutch or differential.During this check, make sure that there are no transverse vibrations during the pull and release stages.With the help of a colleague, check that the noise is not due to one of the dashboard components not being properly fastened (when your hand is placed on top of it the noise either lessens or disappears).If the vehicle is fitted with a sun roof, check that the noise is not being caused by the later by opening and closing it and placing your hand on it to quieten any noise.Increase the speed and check that there is no metallic noise, possibly accompanied by transverse vibrations which vary according to the vehicle speed or engine revs.Brake in safe conditions to check whether the noise is only present during braking as a result of the brake discs.Pull the handbrake lever gently, whilst driving in a straight line, to check whether the noise disappears.Road test the vehicle over an unmade road (transverse rails, paving, cobblestones) to check the type of noise.During this check, make sure that there are no transverse vibrations accompanied by noise.Whilst carrying out the test, steer in safe conditions to determine whether the noise is louder on either of the two sides.In the latter case, the subsequent checks should be carried out more carefully on the side in question.