'06 Fabia 1.2 HTP - droning noise at certain speeds

[HarrisM]

Hello fellow Briskodians!

 

I'm now the proud owner of a Mk1 Fabia and aside from the fact that everything works as expected, it makes a droning noise at certain speeds that sounds like trouble!

 

All speeds mentioned will be as indicated by the speedo, my observations are repeatable and accurate so far.

 

Between 0-25mph everything is nice and quiet, some vibration in the steering wheel that feels like an unbalanced wheel.

 

At around 25-30mph the droning noise starts to fill the cabin, vibration in the steering wheel as at lower speeds.

 

At 40mph the noise reaches its first peak, vibration in the steering wheel slightly more intense.

 

At 45mph the noise reaches its first "trough", noticeably less than at 40mph, vibration in the steering wheel as before.

 

At 50mph the noise reaches its second peak, vibration in the steering wheel is less than at 40mph.

 

At 55mph the noise reaches its second "trough", louder than at 45mph.

 

At 60 mph the noise reaches the absolute maximum intensity I've experienced so far, a loud resonating boom fills the entire cabin. Vibration in the steering wheel is less than 50mph.

 

Accelerating to 65mph the noise exponentially decreases and only leaves a slight hum with no vibration in the steering wheel. This is the sweet spot and is a perfectly acceptable level of cabin noise on the motorway. The hum progressively increases in loudness up to 85mph just as you would normally expect in any car (I wouldn't dare go any faster in this Fabia :D).

 

The variation in noise between speeds is the same both in acceleration and deceleration, the same volume always occurs at the same speeds, very repeatable and very predictable.

 

Additional observations:

 

Engine and gearbox do NOT affect the noise in any way. There is no difference between gears or neutral, the noise remains entirely unaffected at any of the above mentioned speeds.

 

 

Any input is much appreciated, I understand that this may seem like a wheel bearing but the symptoms do not agree,  wheel bearing noise only gets worse with speed, not better.

 

Are these symptoms typical of wheel imbalance, wheel alignment or both? Also are there any telltale signs I can readily observe on the tyres that would help diagnose this?

[Breezy_Pete]

Take any wheel trims off the front wheels, and look around the wheel rims (inner too if poss.) looking for any cleaner areas that might be evidence of a balance weight that has parted company. 

 

If the car is new to you and has never not done this in your ownership, just get the (front) wheel balancing checked, the front wheels/tyres may have come from the back axle and not been balanced when fitted there.

Edited 19 December, 2016 by Wino

[TMB]

Sounds more serious than wheel imbalance to me. I've never known wheel imbalance to cause steering shake as low as 25 mph. It's usually around the 50/55mph mark and with no droning noise.

 

I'd be wary of driving at high speed until you get it sorted. Sounds more bearing related to me.

Edited 20 December, 2016 by TMB

[KenONeill]

As above or tyre(s) saw-toothed or out of round. Both of which are DIY visual inspections.

[HarrisM]

Happy new year to everyone and thank you for your replies!

 

I had some time today to jack up the car and check a few things. The front wheel bearings appear to be fine, there is no play or wobble when the wheel is shaken by hand. There seems to be some looseness in the tie-rod end of the front right wheel but it is minimal. The half-axles on both sides look like new, the dates on them are 03/2006 so I assume they have never been replaced. There is very little backlash in the CV joints, the half axle follows the wheel nice and smoothly when it is rotated by hand.

 

I swapped the tyres back to front, the symptoms described in the first post are more or less the same. One thing I have noticed is that when I drive at 60mph which is the point where the noise is the worst, if I put pressure on the wheel and start turning right, the noise gets better. When I do the same going left, there is no change.

[TMB]

It's a wheel bearing. There doesn't have to be play in a bearing for it to be noisy. I'd say the noisy one is on the right-hand side judging by the fact you say it gets quieter when you steer right because you are relieving the weight of the car on the right side.

Edited 15 January, 2017 by TMB

[Avalon]

Fabia's tend to go through certain things quite often. Drop links (buy Mielle HD's), console bushes (buy Powerflex or at a push cupra solid versions), ARB bushes (Powerflex again), wheel bearings - whoever you buy, they need to use the proper tool to put them in - pressing in = it'll die sooner rather than later.