Strange Rumbling Noise

[Mattf1]

Dear all,

I really hope someone can help.

I have an A4 B8 2,0TDI Avant.  A couple of weeks ago when driving down the motorway I began to hear a strange rumbling noise and thought it was the engine however the noise gets louder the fast you go, if you drive at 60 MPH and put it in neutral the rumbling noise remains, same if you rev the engine, the sound stays the same until you slow down therefore it must be something to do with the moving parts of drive - wheels etc.  I have taken all the wheels off and inspected the tyres, hey are in perfect condition with no bulges of screws etc.  It seems to be getting louder by the day but am reluctant to take it to a garage as will probably charge ridiculous prices!  The more I think about it the more I think it could a warped disc however there appears to be no drag, just a rumble which can be heard upwards of 30 MPH.  MPG and performance too be the same. Do something into the mix when I put the brake on there is a loud whooshing down.  Hope that makes sense!

 

Any ideas or suggestions would be greatly received.

 

Regards

Matt

[Magnet]

Hello Matt,

Not sure if I can help you. Last sentence - sorry, it doesn't make sense to me, but it could be me. 

Could I start by just clarifying that this noise is not there when you rev. the engine at standstill, but only there when the car is moving? If only there when on the move, have you tried (under safe conditions) to deviate off a straight line - to the left and right - when this noise is present to see if the noise gets better or worse? Does the noise vary on cornering? 

Warped discs? I would not have thought so, since you would be more likely to feel a pulsing of the brake pedal.

You seem to have eliminated the tyres, which is always the first port of call, and this may narrow it down to a wheel bearing, or if not that, possibly a drive shaft issue.

Kind regards,

Gareth.

[Dan3222]

I second Gareth here,

If the noise stays almost constant it will be one of the rear bearings. If it gets noticeably louder when turning right it will be the left front bearing, if louder when turning right it is the left bearing (this is because on cornering the weight of the car shifts towards the opposing side of the car.

To diagnose which side of the car the rear bearing is, jack up the back, (leave car in gear and front wheels chocked for safety) release the handbrake and then spin the wheel with your hands. The faulty bearing will be very obvious as you will hear a noise compared to almost zero noise on the good bearing side.

 

Hope that helps.

[Golfer]

Maybe a different problem but I had loud creaking noise from dashboard. Problem was due to faulty rubber dampers on subframe. Once these were replaced it was solved.

[dinnertimedave]

Not much help but I've got what sounds like the same issue. I haven't had the wheels off but I have jacked it up and checked all the bearings, all good. Only very minimal play in the driveshafts, no 'clicking' from the CV joints either. Starts at 25 mph and gets steadily louder, can feel it through the steering wheel too. Got to admit I'm stumped and I'm an ex mechanic 

[Brad-B5]

Hi Matt

I'd say bearings too, is it a deep humbing sound?

Regards

Bradley

[ABDPH2]

On 7/14/2017 at 8:28 PM, Mattf1 said:

Dear all,

I really hope someone can help.

I have an A4 B8 2,0TDI Avant.  A couple of weeks ago when driving down the motorway I began to hear a strange rumbling noise and thought it was the engine however the noise gets louder the fast you go, if you drive at 60 MPH and put it in neutral the rumbling noise remains, same if you rev the engine, the sound stays the same until you slow down therefore it must be something to do with the moving parts of drive - wheels etc.  I have taken all the wheels off and inspected the tyres, hey are in perfect condition with no bulges of screws etc.  It seems to be getting louder by the day but am reluctant to take it to a garage as will probably charge ridiculous prices!  The more I think about it the more I think it could a warped disc however there appears to be no drag, just a rumble which can be heard upwards of 30 MPH.  MPG and performance too be the same. Do something into the mix when I put the brake on there is a loud whooshing down.  Hope that makes sense!

 

Any ideas or suggestions would be greatly received.

 

Regards

Matt

Did you ever find out what this was, same issue. Just had the valves and timing chain replaced. Thinking it might be the alternator pulley, it’s under warranty so I will find out tomorrow.