Hi Claus and
to the forum.
The noise is coming from one
(or possibly both) of the wheel bearings, and this usually occurs when water finds its way inside the bearings, eventually causing rust to form on the metal balls.
There is a large bearing on the brake disc side and a small bearing on the opposite side.
If your bearings are the metal shielded type
(instead of the rubber seal type) water is more likely to get inside the bearing and cause the bearings to fail, especially if a hose pipe or jetwash has been pointed anywhere near them.
If you only have one shielded bearing and one sealed one, the chances are that you will only have one noisy bearing
(which is most likely to be the shielded one) and I strongly recommend that this should be replaced with a rubber seal type.
If both bearings are noisy, you will obviously have to replace both of them to completely cure the noise.
Check out
this post for further information and bearing details.
Please note that the bearings on the MP4 and MP5
(and probably the Smart Pies and Magic Pie Edge too) are the same sizes as the MPIII bearings shown in the above linked post.
Alan
