I have owned my 170 TDI Superb twindoor from new (bought Aug 2010).  I have noticed in the past year or so that I can hear a dull and constant humming noise (comparable to a reverberation) from the rear-left of the car (direction of rear-left wheel) when the speedo hits 65mpg+.  I don't know if this was always the case - I can't specifically recall not hearing it, but it has certainly only started to iritate me in the past 6-12 months.  I am still on the original Continental tyres (I have winter tyres on the car for 4-5 months of each year, so wear is reduced).

 

Just wondering if anyone else has noticed this noise in their Superbs, and also if you have any ideas as to the cause?  It only originates from the rear-left direction (from where I sit in the driver's seat).

 

I generally drive at 60mph on the motorway, and so it does not bother me very often.  But, it would be nice to know why.

 

Thanks for your time.,

Andrew.

I would suggest either a rear bearing or saw-toothed tyre. I had a saw toothed tyre on my Octavia and it was very noisy and rumbly. 

Uneven tyre wear from misaligned wheels can cause this (as above). Have you checked for that?

Saw tooth would be my guess,

 

swap back to front and see if it goes, if it doesn't start looking at the bearing.

Are they Dunlop tyres?  That would be my first suspicion.  They sawtooth like hell!!

Unfortunately a fairly common problem.  Take a look at this: http://www.ukpassats.co.uk/phpbb/viewtopic.php?f=9&t=41805&p=401667&hilit=sawtooth#p401667

 

As above posts, first check is to look at how all 4 of your tyres are wearing.

Thanks guys for the replies.  It's actually going in for its 1st MOT tomorrow morning, so I shall ask mention the noise and your suggestions to the dealer, and let you know the outcome.