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Strange droning noise

GP41

Well-known member
Joined
19 Oct 2014
Messages
476
I've got a strange droning sound - worse on the front offside of our 54-plate Audi A4. It similar to the noise that old Land Rovers make when they drive past. I've been out with my mechanic friend and he thought it was tyre-related but there was nothing obviously wrong. First noticed about 4 months ago. We decided to leave it and just see if it got worse or more symptoms emerged.

I've just noticed that the nearside front wheel is significantly dirtier than all the others. Could there be a link? I thought I'd check whether the dirt was dust or grease as that could point to it being something other than brake dust (CV boot?).

Any bright ideas? I'm not massively worried but it's annoying and I start thinking about it again every time we contemplate a long journey in it.
 
Is it your wife.........mine seems to make a similar noise 90% of the time!

Wheel bearing or seized brake caliper - if it the brake caliper it may be pulling to one side when brakes applied with vigour.....
 
:hand: I was so tempted to say I'd checked and it wasn't the wife!

I did try the hard braking and it didn't seem to veer off at all. Might try that again though.

Thanks Colin
 
Hi

Just to help us in giving you suggestions :

Drive it and listen to the questions
Engine fault finding questions

Is it droning on idle whilst parked?

Is it droning more when parked but increases with revs?

Does it only drone when mobile?

Is there a remarked difference in sound increase when driving at 30mph in 2nd gear or lower revs in 4th or 5th gear?

Transmission questions :
Is there any difference of sound pitch whilst maintaining a constant speed but running a high gear or low gear?

When mobile find a long hill to coast down with the engine running, is the noise there? And staying in neutral does it increase in noise pitch as the vehicle increases speed in neutral?

Whilst coasting in neutral downhill, pop it into 3rd gear, does the noise then begin?

Brakes:
Drive down a hill in 3rd (whilst no one is behind you) and apply a left foot brake gently enough that you can feel the pads trying to retard the speed, but keep the acceleration going (ie demand both. Brake and Power. Does the droning stop with brakes powered up onto the disks?

A scenario like this is to use a rolling road like they have in MOT test centers. It'll help diagnose the cause of lot easier.

There's a lot of investigation questions above I know, but it'll help you to gain a lot of information as to the cause and different ways to replicate and eliminate.

Let us know how you're able to specifically able to replicate the noise without incorporating different scenarios.

All the best

:thumb:
 
ColinC said:
Is it your wife.........mine seems to make a similar noise 90% of the time!

Beat me to it, although mine isn't a wife just yet.

:lol:
 
MNC911 said:
Hi

Just to help us in giving you suggestions :

Drive it and listen to the questions
Engine fault finding questions

Is it droning on idle whilst parked?

Is it droning more when parked but increases with revs?

Does it only drone when mobile?

Is there a remarked difference in sound increase when driving at 30mph in 2nd gear or lower revs in 4th or 5th gear?

Transmission questions :
Is there any difference of sound pitch whilst maintaining a constant speed but running a high gear or low gear?

When mobile find a long hill to coast down with the engine running, is the noise there? And staying in neutral does it increase in noise pitch as the vehicle increases speed in neutral?

Whilst coasting in neutral downhill, pop it into 3rd gear, does the noise then begin?

Brakes:
Drive down a hill in 3rd (whilst no one is behind you) and apply a left foot brake gently enough that you can feel the pads trying to retard the speed, but keep the acceleration going (ie demand both. Brake and Power. Does the droning stop with brakes powered up onto the disks?

A scenario like this is to use a rolling road like they have in MOT test centers. It'll help diagnose the cause of lot easier.

There's a lot of investigation questions above I know, but it'll help you to gain a lot of information as to the cause and different ways to replicate and eliminate.

Let us know how you're able to specifically able to replicate the noise without incorporating different scenarios.

All the best

:thumb:

Thanks - some good material to work with there. I'll try to get out in it some time today and have another listen.

Cheers, GP
 
Check the tyre condition... run your hands around the tread, see if it has a 'sawtooth' profile. This gives rise to a hum as effectively you are driving on a serrated surface.

Also, after a drive, check the temp of the wheels. If a caliper is sticking, the wheel will be noticeably warmer than the others.
 
Robertb said:
Also, after a drive, check the temp of the wheels. If a caliper is sticking, the wheel will be noticeably warmer than the others.

Amen to that, a friend gave us a lift to the airport once in his EP3, he was driving at 1pm on a Saturday at silly speeds. And when I asked him why he was going so fast in broad daylight at primetime speed trapping hours, he said "this is the best time to speed". Odd!

I digress, anyways, we came off the M11 towards Stansted and the car was making a horrible noise/rumble from the rear, the tyre sidewall had completely failed, looked like nothing I had seen before. His offside caliper had stuck and heated things up so much, the tyre failed. Incredible to think how fast he had been going not much before that.
 
The return of Marty Wild said:
Amen to that, a friend gave us a lift to the airport once in his EP3, he was driving at 1pm on a Saturday at silly speeds. And when I asked him why he was going so fast in broad daylight at primetime speed trapping hours, he said "this is the best time to speed". Odd!

Ah, the old 'hiding in plain sight' strategy.

Or maybe he was assuming some sort of 'safety in numbers' argument that the more cars on the road, the less likely he would be to be caught. :dont know:
 
GP41 said:
MNC911 said:
Hi

Just to help us in giving you suggestions :

Drive it and listen to the questions
Engine fault finding questions

Is it droning on idle whilst parked?

Is it droning more when parked but increases with revs?

Does it only drone when mobile?

Is there a remarked difference in sound increase when driving at 30mph in 2nd gear or lower revs in 4th or 5th gear?

Transmission questions :
Is there any difference of sound pitch whilst maintaining a constant speed but running a high gear or low gear?

When mobile find a long hill to coast down with the engine running, is the noise there? And staying in neutral does it increase in noise pitch as the vehicle increases speed in neutral?

Whilst coasting in neutral downhill, pop it into 3rd gear, does the noise then begin?

Brakes:
Drive down a hill in 3rd (whilst no one is behind you) and apply a left foot brake gently enough that you can feel the pads trying to retard the speed, but keep the acceleration going (ie demand both. Brake and Power. Does the droning stop with brakes powered up onto the disks?

A scenario like this is to use a rolling road like they have in MOT test centers. It'll help diagnose the cause of lot easier.

There's a lot of investigation questions above I know, but it'll help you to gain a lot of information as to the cause and different ways to replicate and eliminate.

Let us know how you're able to specifically able to replicate the noise without incorporating different scenarios.

All the best

:thumb:

Thanks - some good material to work with there. I'll try to get out in it some time today and have another listen.

Cheers, GP

Just been out. Bizarrely it seems much less noticeable than when I last drove it. Previously I was having to get to 40 to bring it on but I was nearer 70 tonight when I started noticing it. To answer some of the questions:
- it only does it when mobile
- it doesn't change when you depress the clutch or put it into neutral
- it doesn't change pitch when you change gear
-it didn't have chance to find a long enough hill to drive down at 70+ in neutral to test that.

So it seems to be wheel-speed-related rather than engine-speed-related.

I tried the left foot braking thing but didn't notice any change - a bit tricky trying to do this at 70+ with nobody behind me!

I tried braking fairly hard to see whether the car veered off but it stayed in a perfectly straight line.

I can only imagine this is tyre related but not sure why it would improve over time - unless the tyre had somehow become misshapen and has returned to a better state ???

I'll check tyre condition when I get a chance in daylight. I don't remember noticing anything untoward when I checked pressure and tread quite recently.
 
Hi GP

Well actually that's good news to a certain degree. As you can potentially rule out the engine and and gearbox.

I wouldn't have thought it was bearings as they tend to squeal (however they can be over looked and hard to replicate) as I found out on an old 986. That's not to rule them out though.

Brakes are a clear giveaway, you can wash the internal alloy faces up, take the car for a spin around some tight twisty country lanes, where you'll be using a lot of brake pad effort. Upon arriving home it'll be identified with lots and lots of dust. If your vehicle has drilled discs they act like a cheese grater and make it even more easier to identify a cause with even more dust.

(please don't drive at 70mph and try LFB, it can cause Insurance phone calls) I was thinking 10mph, max 20mph and with no one around you.

If it's wheel speed related, you think, avenues of investigation:

1, Drive shaft
2, Tyre
3, Check for any heavy scoring on the disks for either deep scoring or cracks etc
4, Pad thickness depth is a good check for differences
5, Loose under trays can cause the passing air to emit a drone, rather similar to roof racks cause.
6,Cooling fans are also a hard to spot item as they're not rotating all the time, only as per temperature demands it.
7, I did think about the possibility of being exhaust related, either a small hole maybe on a 54 Plate. Or maybe as it gets hotter with driving it's expanding the material and possibly a flange joint opening slightly.
8, Heater blowers, on-off, left on for a long period
9, Air con, they make a good drone when work is required
A few of the above can be eliminated by listening to the noise. Whether what you are changing is changing the pitch of the noise, ie increasing speed, temperature from cold to optimal. Or whether above lets say 30mph no matter what you do the noise remains constant.

There's certainly a few item's to look and try and recreate with
:thumb:
 
Brilliant, thanks. That's me sorted for the weekend then :thumb:

I'll let you know if I get any further with it. I've a long run planned in a week so hopefully it'll give me chance to try out a few things ( but no left foot braking, I promise :eek: )
 
Brilliant, thanks. That's me sorted for the weekend then :thumb:

I'll let you know if I get any further with it. I've a long run planned in a week so hopefully it'll give me chance to try out a few things ( but no left foot braking, I promise :eek: )
 

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