Member Since: 04 Jan 2010
Location: chester
Posts: 15
rattle or resonance sound when increasing speed
Help please. Local stealer have scratched thgeir heads on this one and replaced a propshaft bearing stating the problem was now solved and oooohhh nooooo its not.
A resonating rattle occurs at certain speeds when foot is on the accelerator enough to make the speed increase (probably makes the nosie when accelerating hard too but noise of engine drowns it out) Its most noticable around the 40-50 mph mark but is noticeable up to 70 and down to 30. It doesn't change frequncy when increasing the speed and stops when taking foot off the pedal slightly. It will return when pressing again slightly, its almost controlable in this way. At first I thought it was a resonating heat shield or soemthing (and thats the best way to discribe the noise - sort of metallic).
Any ideas? Thanks
9th Aug 2010 12:53 am
Bushwanderer
Member Since: 27 Nov 2007
Location: Northern Rivers, NSW, Australia
Posts: 2050
Catalytic converter?The Bearded Dragon
10th Aug 2010 6:46 am
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
Thanks how do I check the cat? By the way forgot to say the noise doesn't occur if I rev in neutral.
10th Aug 2010 11:26 am
Bushwanderer
Member Since: 27 Nov 2007
Location: Northern Rivers, NSW, Australia
Posts: 2050
! That makes it tricky - for all sorts of possible causes.
As you have said, it is only under load (accelerating).
Have you tried holding in different gears and see if the symptoms are road speed or rev dependent?
Try checking the fitting of the heat shields in the engine bay.
Best Wishes,
Peter
PS: As you can see, I'm scratching my head on this one, hopefully someone else will give you some advice.The Bearded Dragon
11th Aug 2010 3:14 am
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
Checked heat shields and seem ok. Its an auto but tried holding in gear and its definitely not road speed related as just a touch on the pedal brings the noise back with no noticeable change in road speed it goes away again when I come off the pedal. This is doing my head in too.
11th Aug 2010 11:48 am
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
For those who are interested the dealer has investigated, to be fair very thouroughly, and their conclusion is that the fuel pump is making the noise. My car is 2005 reg and apparently the fuel pump was changed on new models after 2007 but this was for a different reason . they compared the noise of my car with other discos of the same age and the noise is exactly the same, most prominent with the windows open and crusing with a light tough on the pedal at 50 mph. the noise is not apparent on models after 2007 and appears to be more notcieable on autos before 2007 rather than manuals. It wasn't clear why this would be the case but I heard the noise on a different car too and unless we both have the same fault then it is something that comes as standard. their conclusion was nothing needs doing and changing the fuel pump wasn't an option. Anyone got any wise words to add?
2nd Sep 2010 2:40 pm
PaulP
Member Since: 04 May 2007
Location: Barcelona
Posts: 4317
Hi Mike,
europeancemike wrote:
This is doing my head in too.
europeancemike wrote:
their conclusion is that the fuel pump is making the noise.
.....
their conclusion was nothing needs doing and changing the fuel pump wasn't an option
To be fair, if it's doing your head in, then it's because it is annoying and you can obviously notice that there is something wrong.
If they conclude that the noise is coming from the HPFP, then why the hell do they say that changing it is not an option? Something doesn't sound right
There was a TSB about faulty fuel pumps on MY08 models (or something like this) due to degradation of the bearings causing noise and also squirting fuel over the engine (catching fire in some cases).....although you might be out of the VIN range, it may have been widened recently - ask them to check...
Just out of interest, does switching the climate/air-con OFF help to quieten down the noise?
Another option would be to try another dealer if that is a possibility for you. 2006 Discovery 3 TDV6 SE AutoBuckingham Blue 2007 Golf GT DSG
2nd Sep 2010 3:33 pm
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
The aircon being off doesn't make any difference. I think the model 08 year has a different fuel pump due to the new fuel injection system from 07. as you have an 06 auto does your car make this noise? i went out with the dealer in anoth 05 car and it had the same noise as mine at 50 mph most often and at lower speeds but not so easy to pick up because it doesn't last very long when you release the pedal slightly but at 50 mph you can defintely control the and create the noise with the throttle pedal. Might try the new dealer suggestion when my dubloon bucket is replenished.
2nd Sep 2010 4:14 pm
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
I thought I would update to say the problem is still here but would very much like to hear from anyone with a pre 2007 auto to let me know if they too have the same noise. At least then I can take comfort from the fact we all have the same issue and can share the pain.
3rd Jun 2011 10:25 am
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Member Since: 06 Nov 2006
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Quote:
It doesn't change frequncy when increasing the speed and stops when taking foot off the pedal slightly. It will return when pressing again slightly, its almost controlable in this way
Clock/ SNOTM /3Flash / 4x4Info /BT Update /Service Reset/Error Codes / Gearbox Reset See It Here
3rd Jun 2011 11:28 am
crwoody
Member Since: 09 Mar 2009
Location: Littleborough
Posts: 2109
Not sure if it's the same noise but mine makes a low droning sort of noise at similar speeds under gentle acceleration, I found on mine that it's actually engine speed related and only occurs at around 1400 - 1500 rpm, once over that speed it's gone.
Definitely sounds like some kind of resonance - but no idea where from.
Edit; ISTR there are one or two other threads on here alluding to a similar "issue"?Clive
3rd Jun 2011 1:07 pm
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
Can you control the noise with the accelerator pedal around 50mph? The best way to describe it is drive with the drivers window down, slowly increase speed to about 50mph and at some point there will be a distinct metallic resonance sound, if its the smae as mine then this will dissappera if you press the pedal and go faster but come back if you come off the gas slightly, almost controllable with very light presses of the accel pedal. its not the diff.
3rd Jun 2011 1:23 pm
crwoody
Member Since: 09 Mar 2009
Location: Littleborough
Posts: 2109
I can't say that I've listened to it with the window down, or that it's a metallic sound, just a dull drone sort of noise (from inside the cabin,) I can control it with a gentle touch of the gas pedal as you say but the actual road speed at which it occurs is depending on what gear you're in, as I said, on mine it seems to coincide with a specific engine speed.
TBH, it's been there since I got the car and I tend to ignore / not notice it now, bit like a ticking clock - just hope it's not a ticking time-bomb
It it's a metallic sound it could be something like a loose exhaust heatshield?Clive
3rd Jun 2011 2:10 pm
europeancemike
Member Since: 04 Jan 2010
Location: chester
Posts: 15
sounds like you have a similar thing, mine is all through the range once you are listening for it but most noticeable at 45-50. I have tended to believe the dealer (see earlier post of mine) that its the fuel pump/valve switching which was replaced on newer 2007 models with the new fuel injection system. not sure I entriely understood but I did hear it demonstrated on another 06 disco. I am not convinced it was there from new though otherwise it would have been well known by now. It was new to the two dealers as well so it might just becoming apparent as certain parts wear out or bits fall off in the rain. Any dealers/service bods out there that would car to pass comment? thanks
3rd Jun 2011 2:20 pm
mayhem
Member Since: 07 Aug 2010
Location: Hampshire
Posts: 5
I have played this game for almost 5 months with my local dealer. I get the same noise between 1350-1500RPM when the vehicle is under light load, once above 1500RPM its gone, the noise is tinny and i can feel the vibration through my left foot when its on the foot rest. I discovered that the vehilce was aways in 5th when i got this rattle by testing it at various speeds in auto and using command shift. I could bring the noise on almost at will in command shift and 5th. I have left the vehicle with the dealer for about 2-3 weeks in total over time and they have replaced the torque convertor, messed about with the prop shaft and reset the gearbox actuators and still no joy. I too have driven another vehicle to see if it was limted to my car but the other vehicle, a car on sale with the dealer, also had a similar problem. I then took one of the dealers experienced guys out for a test drive with me and he diagnosed a potential exhaust rattle which turned out to be a heatshield problem and a gearbox mount. To be fair the problem did go away for a month but is now back, so im resigned to the fact that there is a design flaw / feature in the vehicle that just cant be dialled out.
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! That makes it tricky - for all sorts of possible causes. 
