Humming noise between 30-50mph

[samsland]

Hi all - This is my first post here and I'm completely stumped by a problem my Skoda Octavia Elegance TD 2.0 (2014) has developed.

 

I've owned the car for a little over a year and am the second owner following the 1st handing it back following a pcp contract.  The car has generally been fantastic but I'm quickly falling out of love with it.  I had the dreaded water pump failure that resulted in coolant leaks that the forum allowed me to self-diagnose, this was in February and I had the timing belt done at the same time alongside the oil change for the automatic gear box.

 

Fairly soon after this work (but not necessarily the cause?!), the car started to whine/hum in a kind of harmonic resonance way randomly, but reliably, at speeds between 30-50mph.  The noise is unconnected to drive and can occur if without acceleration.  I have had the car back to the dealers twice.  The first time the dealers checked the bearings and all sounded normal to them.  Their advice on this trip was to replace all 4 tyres, two of which were advisories but the rear two were ok and this was more down to their age/ quality.  So 4 new tyres later and nearly £300 less in the wallet, the noise is as loud as ever and it's clearly completely unconnected.  I then take it back to the dealers again and insist on a senior mechanic test driving it with me.  They agree and he can hear the issue but has no idea as to the cause.  He tests the bearings by some pretty aggressive turns and doesn't believe the noise sounds consistent with a wheel bearing issue.  He then puts it up on the ramp and noticed a rear wheel is slightly buckled, though nothing major.  They won't try out another wheel but quote me £350 for a replacement to which I say no.  I get home and jack the car up myself, spin both rears and they sound fine.  I then replace the buckled wheel with the spare saver and, you guessed it, the noise is still there.

 

I've been out this evening and taken a sound recording of the noise.  Any help my the gurus here would be hugely appreciated.  I've spent c.15% of the car's cost on services/ these attempts to fix the issue, but to no avail!  I know the noise doesn't sound like much but it sure wears on you when driving around suburbia.  I'm getting to the point where I'm just going to trade it in, which feels incredibly needless given how much I've spent on it.

 

Thanks kindly for any help.  Sam

octavia noise.m4a

[Esseesse200]

What did the rear thee look like when the case off. I would say a hunter 4 wheel alignment to start with that may solve a lot of issues mate. I known. The two words kwik and fit make us twitch and wince but to be fair their machine are spot on awesome. It should have completely adjustable camber and toe on the rear end 

[coloneldolomite]

I struggled to get Skoda to replace the front wheelbearings on my Octavia - very similar sound at exactly the same speeds you refer. They too advised tyres - replaced = still the sound persisted.

In the end out of frustration, I got an independant to replace both fronts - even they were not convinced after the aggressive turns test too, however the noise had gone.

 

That was at 40,000 miles - now at 85,000 the noise is back and funnily enough it is in today to have the o/s front bearing replaced again!

 

A well known issue and if you have tried everything else it may be worth a go. Best of luck.

 

[DEZMONDE]

Check for saw toothing of tyres, when it happens it sounds like bearings failing.

Not sure if it's as common on mk3 vs mk2 though.

 

Dez

[samsland]

Thanks for the responses so far.  Quite soul destroying but I guess everything in perspective!  The noise is definitely coming from the rears but I can't figure out which side.  I may just get both bearings done and see what happens but don't want to spend money for the sake of it.  I'll also pop it down to Kwik Fit to see what their view on the alignment is but I struggle to see a link between alignment and the noise.  More later, cheers!

[coloneldolomite]

I picked my car up tonight following the bearing replacement and was amazed at the difference. So much quieter now. I hope the bearing replacement sorts your problem. My independent garage were able to test which one it was and it turned out to be nearside rather than offside that was noisy to my surprise. It can be difficult to detect from inside. 

[shrikep15]

As DEZMONDE has already mentioned, rear alignment could well be the cause of this noise.  My mk 2.5 vRS was always noisy at motorway speeds which I put down to the horrible original Dunlop Sport tyres it left the factory with, as these were always known to be noisy.  After picking up a rear puncture when the car was about 18 months old I found the inside shoulder of both rear tyres were sawtoothed.  The dealer wasn't particuarly interested, but when I pushed and showed them  a thread from here discussing the problem they eventually agreed to a four wheel alignment.  This definitely reduced the noise but unfortunately didn't eradicate it.  I eventually replaced all 4 tyres about 2 years ago with Goodyear Eagle F1 3's and had the alignment checked again (it was only fractionally out) and the car was transformed, so much quieter and acutally rides and tracks better.

 

I know the vRS has a different rear suspension setup to the Elegance, but I would still recommend having it checked, and make sure to go somewhere with a proper Hunter 4 wheel alignment equipment.

Edited 24 May, 2019 by shrikep15

[benterrier]

2 back axle types are being discussed here. To my knowledge no adjustments are possible to the beam type which the topic item has, so is 4  wheel alignment  only going to give you a check, what do you do if something is out of line. 

I have a 18 plate 2.0l Tdi and have the mentioned Dunlop sport tyres. The noise from these is only acceptable on only the best of road surfaces, other than this the car feels planted on the road and is great drive. Having only done 6k don't think the wheel bearings are an issue. What tyres would be a quieter alternative. 

[shrikep15]

Goodyear Eagle F1 would be my recommendation, I have the 3's but there is a new 5 available.