I've been getting a pulsing rumble between 20-25 mph for a few months. it's not there below or above these speeds. at the last service, the dealer couldn't find anything, but I suspect that's more to do with the dealer than the fault...

Any ideas about what it could be? It feels as if it's coming from the rear left, and it's not the tyre on that wheel. because I got a puncture recently and the spare went on with no change in the sound.

had the same problem, sounded like a wheel bearing. Found that the indise edge of one of my rear tyres had worn unevenly causing the noise. When i ran my hand over it, it feltlike the tread was stepping rather than being flat. Hard to explain!

Sawtoothed tyres - very common issue.

lots of threads on it.

your geometry needs checking.

Common issue with the car and all vw cars which used this chassis design - it seems to develop as the tyres wear and can be helped by ensuring that the geometry is correct, some threads will have suggestions that different tyre brands are better at supressing the noise, part of the problem is that there isn't enough insulation keeping out road noises etc in the design. If bearings are worn the noise generated is usually much worse as you go around corners. Check other threads for advice and ideas, if a dealer pretends not to know about this he must have been in hiding on the dark side of a distant planet.

Edited 16 November, 201015 yr by hugothebear

I had this problem when I test drove my Octavia. The garage had a look and the rear tyres were worn strangely with odd bald spots on the insides. They put new tyres on for me and the noise disappeared. I later found on here that it is known as 'sawtoothing' and is caused by the geometry being wrong. I took it to a geometry specialist who set the geometry correctly and I've noticed a definate improvement in the handling (more planted on the road).

Take it to a good geometry place and get it fixed if your tyres have this wear pattern. It'll improve the handling and save your next set of tyres from wearing prematurely.

Edited 16 November, 201015 yr by pixor

Thanks, Anyone got any recommendations for geometry specialists in the central belt of Scotland?

If you are prepared to go to Edinburgh, then I would recommend Willie at C.L.C.M Wheel Alignment Ltd, 11 Bankhead Drive, Sighthill Industrial Estate, Edinburgh, Midlothian EH11 4EJ Tel: 0131 458 5559. That's where I got mine done, and he's excellent. Took about 30 minutes. It's just off the A720 near Hermiston Gait, so it's easy to get to without going into Edinburgh.