I've noticed a strange but quite loud humming that occurs when I get up to around 60mph in my Octavia. I have a 2.0 tdi DSG (06 plate). I noticed a while ago that I only have one rear mud flap. Haven't had the car long (since feb) it looks like someone took off one of the mudflaps (maybe during service) and forgot to put it back on - can't believe I didn't notice when I picked the car up! As a result the rear wheel arch liner on the drivers side is missing approx 3 screws and has some play in it. Any chance this could be the source of the hum at high speeds? I've been in the process of moving home and haven't had a chance to get down to the dealers to pick up some screws (and maybe a new mud flap set). I'm just hoping the hum isn't the sympton of something worse.....

Edited 27 July, 201114 yr by Plod

I would have thought it's the rear tyres, check the inside edge and you'll find the tread is stepped and uneven. This is known as sawtoothing and it common to the model, getting the rear camber checked and adjusted will help as will checking tyre pressures regularly.

It will be the sawtoothing tyres.

What have you got on there at the moment?

I agree with the other guys, had these symptoms myself on my old 2.0 TDI Octy, inside of the rear tyres were turning into 50p's!

I recently had the fronts replaced and the fronts put on the back. So the rears are the fronts that the car had when purchased and they are intesa sava. I'm afraid I went for the cheapo option on the front so they are Rikens. I had all the wheels balanced at the same time and tracking checked on the front.

I would rather not have to replace all 4 tyres at the same time. I've looked at the tyres and can't see obvious sawtoothing but then I probably wouldn't know it if I saw it!

Was told at the time that the tyres that are now on the rear were fine and that was about 2 months ago. Seem to have plenty of tread on them. Any recommendations for rear tyres?

Get the rear suspension settings checked, on a 4-wheel alignment machine.

It could be that the noise is now apparent because you've swapped tyres and they'll have worn in a particular way on the front axle, before being swapped onto the back.