2010 Q7 noises
07-19-2010, 04:32 PM
#1
Audiworld Junior Member
Thread Starter
Join Date: Apr 2010
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
2010 Q7 noises
Just finished running in my 2010 Q7 3.0TDi and it's developed an annoying intermittent noise.
Sounds like someone hammering tacks into a piece of wood, appears to emanate from underside rather than engine bay, but could just be that it's echoing under the vehicle. Generally manifests itself only between 20 - 35 MPH and with drive 'engaged' (acceleration either soft or heavy) or coasting. Occurs in all gear modes (D, S and manual tip) and mostly in 5th gear (6 speed box). No warning lights, no vibrations, no handling/braking or apparent drive problems.
Had a grope round underside (the lift setting makes it easy) and all the drivetrain seems solid and nothing obvious there.
It's only 3 months old and I'm hesitant about taking it back to the local stealer as past experience has shown they couldn't find a bottle of beer in a bar (don't get me started on their countless incorrect attempts to diagnose the problem on my 2006 A6)... so I want to see if I can suss it out myself rather than hand it over to them to trash the vehicle completely!
Any suggestions greatly appreciated.
Sounds like someone hammering tacks into a piece of wood, appears to emanate from underside rather than engine bay, but could just be that it's echoing under the vehicle. Generally manifests itself only between 20 - 35 MPH and with drive 'engaged' (acceleration either soft or heavy) or coasting. Occurs in all gear modes (D, S and manual tip) and mostly in 5th gear (6 speed box). No warning lights, no vibrations, no handling/braking or apparent drive problems.
Had a grope round underside (the lift setting makes it easy) and all the drivetrain seems solid and nothing obvious there.
It's only 3 months old and I'm hesitant about taking it back to the local stealer as past experience has shown they couldn't find a bottle of beer in a bar (don't get me started on their countless incorrect attempts to diagnose the problem on my 2006 A6)... so I want to see if I can suss it out myself rather than hand it over to them to trash the vehicle completely!
Any suggestions greatly appreciated.
07-19-2010, 06:27 PM
#2
AudiWorld Super User
Yikes. Well, whatever it is it sounds pretty serious... I would get it to the dealer at least to start getting it documented. If you ever have to go to AOA to get help, the more documentation you can provide the better.
07-20-2010, 04:25 AM
#3
Does the noise vary with engine speed? This would narrow it to valvetrain or exhaust system.
Does the noise vary with road conditions? Pavement? Bumps? This would narrow it down to suspension and tires.
Does the noise go away or get worse in turns? This would narrow it down to wheel bearings and drivetrain.
Does the noise go away when you apply brakes? This would narrow it down to - of course brake system.
Does the noise vary with road conditions? Pavement? Bumps? This would narrow it down to suspension and tires.
Does the noise go away or get worse in turns? This would narrow it down to wheel bearings and drivetrain.
Does the noise go away when you apply brakes? This would narrow it down to - of course brake system.
07-20-2010, 08:15 AM
#4
AudiWorld Member
Join Date: Sep 2009
Posts: 108
Likes: 0
Received 0 Likes
on
0 Posts
Does the noise vary with engine speed? This would narrow it to valvetrain or exhaust system.
Does the noise vary with road conditions? Pavement? Bumps? This would narrow it down to suspension and tires.
Does the noise go away or get worse in turns? This would narrow it down to wheel bearings and drivetrain.
Does the noise go away when you apply brakes? This would narrow it down to - of course brake system.
Does the noise vary with road conditions? Pavement? Bumps? This would narrow it down to suspension and tires.
Does the noise go away or get worse in turns? This would narrow it down to wheel bearings and drivetrain.
Does the noise go away when you apply brakes? This would narrow it down to - of course brake system.
Does the noise appear more when steering wheel is turned, i.e. when you apply power and car is turning? Ihis would narrow it down to CV joint problem in front.
Arrie
07-20-2010, 09:32 AM
#5
Audiworld Junior Member
Thread Starter
Join Date: Apr 2010
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
Doesn't go away when applying brakes (other than when car slows down to around 20 MPH noise disappears), turning or with differing road conditions... but you've raised a question there that's got me thinking... does the noise vary with engine speed!
My initial thought is no, I think it varies more with road speed (which should take the engine out of the equation).
Gonna take it out for a spin and see if I can narrow it down a bit more precisely... will report back on findings.
Thanks to all for comments... greatly appreciated!
My initial thought is no, I think it varies more with road speed (which should take the engine out of the equation).
Gonna take it out for a spin and see if I can narrow it down a bit more precisely... will report back on findings.
Thanks to all for comments... greatly appreciated!
07-21-2010, 06:52 AM
#6
AudiWorld Super User
Thats Diesel knock/crack or clatter. It occurs as the engine changes its combustion status (for want of a better way to describe).
It is perfectly normal. Only happens as you change from overrun to gentle power. Its not bad diesel or engine fail. If you drive harder or more agressively you just never hear it. I get it at one spot on the nearest roundabout almost every time (4 years) but rarely even notice. Maybe certain weather conditions/atmospherics make it more audible?
Dont worry about it!
It is perfectly normal. Only happens as you change from overrun to gentle power. Its not bad diesel or engine fail. If you drive harder or more agressively you just never hear it. I get it at one spot on the nearest roundabout almost every time (4 years) but rarely even notice. Maybe certain weather conditions/atmospherics make it more audible?
Dont worry about it!
07-21-2010, 09:46 AM
#7
Audiworld Junior Member
Thread Starter
Join Date: Apr 2010
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
Funny you should mention that... I was reading another thread and got sidetracked onto a linked article on the difference between turbochargers and superchargers (seems to be an increasingly discussed topic with Audi's upcoming 2011 releases) which in turn spun off to an article about combustion and the 'knock' I think you're describing, which I'd never heard about before... so you may well be spot on there.
Will read and digest the aforementioned article with brain a bit more engaged.
In any case got a few more things to ponder now when this next occursI
Thanks again for suggestions... great things these forums.
Will read and digest the aforementioned article with brain a bit more engaged.
In any case got a few more things to ponder now when this next occursI
Thanks again for suggestions... great things these forums.
Trending Topics
07-22-2010, 10:45 AM
#8
Audiworld Junior Member
Thread Starter
Join Date: Apr 2010
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
OK... having gone from knowing very little about diesels (having always been a true 'petrol' head) to 'armchair expert' following over 6 hours of reading numerous web articles on just about every aspect of the same, I can without doubt confirm that what I'm hearing is indeed diesel 'knock'... most notably confirmed after watching (and listening) to a couple of postings on You Tube.
So nice one Justforfun!
I am still a little concerned however about some of what I've gleened from these articles.
Knock is widely acknowledged as being [to a degree] unavoidable in diesel engines due to their method of operation (injection occurring at near TDC), but also as being from inconsequential to totally destructive... I can't find opinion on this leaning more in either direction.
I understand that Audi (along with many other manufacturers) have a 'knock' sensor fitted to their engines to monitor and correct this very problem... so I begin to wonder if mine is faulty or if there's a problem with the injectors as when the noise starts, it can sometimes continue for several minutes/some distance (although still never on idle, only when at a constant speed between 20 - 35MPH).
My locality by nature (Jersey, Channel Islands, the one New Jersey is named after - just thought I'd get that one in) is littered with Audi Q7's, Porsche Cayenne's, VW Toureg's and the hundreds of other vehicles that share the VAG 3.0TDi, as well as BMW X5's and Range Rover Sport TDV6's (the latter being as common as a daily newspaper over here), and I can't say I've heard the unrefined banger racer racket that emanates from my engine coming from any other vehicles of the same ilk.
Maybe you're right... it's nothing to worry about... but should I take the chance?
So nice one Justforfun!
I am still a little concerned however about some of what I've gleened from these articles.
Knock is widely acknowledged as being [to a degree] unavoidable in diesel engines due to their method of operation (injection occurring at near TDC), but also as being from inconsequential to totally destructive... I can't find opinion on this leaning more in either direction.
I understand that Audi (along with many other manufacturers) have a 'knock' sensor fitted to their engines to monitor and correct this very problem... so I begin to wonder if mine is faulty or if there's a problem with the injectors as when the noise starts, it can sometimes continue for several minutes/some distance (although still never on idle, only when at a constant speed between 20 - 35MPH).
My locality by nature (Jersey, Channel Islands, the one New Jersey is named after - just thought I'd get that one in) is littered with Audi Q7's, Porsche Cayenne's, VW Toureg's and the hundreds of other vehicles that share the VAG 3.0TDi, as well as BMW X5's and Range Rover Sport TDV6's (the latter being as common as a daily newspaper over here), and I can't say I've heard the unrefined banger racer racket that emanates from my engine coming from any other vehicles of the same ilk.
Maybe you're right... it's nothing to worry about... but should I take the chance?
07-23-2010, 10:17 AM
#9
AudiWorld Super User
Its amazing how many Q7s you have squeezed onto that tiny island.
Maybe it needs a good burn somewhere above 40mph
You could try a different diesel just out of curiosity but best to ask a regular TDI driver or mechanic what they think.
Off topic bit: Stayed in La Haule Hotel, loved Jersey and yes you have some niiice cars there!
Maybe it needs a good burn somewhere above 40mph
You could try a different diesel just out of curiosity but best to ask a regular TDI driver or mechanic what they think.
Off topic bit: Stayed in La Haule Hotel, loved Jersey and yes you have some niiice cars there!
07-23-2010, 05:01 PM
#10
Audiworld Junior Member
Thread Starter
Join Date: Apr 2010
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
Hour on ferry to France... so think I might take it for a burn soon. Needs motorway action for the particulate filter to do it's work anyway. Still can't believe over 1100 miles on the clock and run your finger round inside of those lovely baked bean tin size tin chrome exhaust trims and.... nothing! Soot free environment.
Will be monitoring the noise carefully this weekend. Stealer's service dept. open tomorrow morning so might go bug their diesel mechanic.
My business just down road from La Haule, 5.30 every night it's just a procession of 911's, Ferrari's, Lambo's, Bentley's and Aston's and now R8's screaming past as all the overpaid bank ***'s head home... I'm just jealous.
Useless fact... at last census, approximate population here 88,000, number of cars registered 110,000+... so you can see why there's no chance of going above 40MHP.
Top pic from the castle by the way.
Will be monitoring the noise carefully this weekend. Stealer's service dept. open tomorrow morning so might go bug their diesel mechanic.
My business just down road from La Haule, 5.30 every night it's just a procession of 911's, Ferrari's, Lambo's, Bentley's and Aston's and now R8's screaming past as all the overpaid bank ***'s head home... I'm just jealous.
Useless fact... at last census, approximate population here 88,000, number of cars registered 110,000+... so you can see why there's no chance of going above 40MHP.
Top pic from the castle by the way.