Possibbly one for Tame Technician, vibration at the front
Discussion
Hi
The car is an A6 2003 with the 2.5 TDI v6.
The problem I'm having is a small amplitude vibration coming from the front of the car noticeable mainly on motorway. The vibration is enoying and spoiled the ride. It make the satnav vibrate for example
I feel the vibration with my feet, not through the steering wheel and not through the seat.
The intensity and frequency of the vibration are the same when doing 60mph or 80mph but the intensity seems to be greater when accelerating.
During the last service the front wishbone link near side and off side where changed.
I am wondering if the upper front and rear link should have been changed at the same time.
Would a worn front and rear link could cause a vibration which shake the front of the car?
Is there a way of checking if the links have abnormal play in them?
Thank you for your help
Jack
The car is an A6 2003 with the 2.5 TDI v6.
The problem I'm having is a small amplitude vibration coming from the front of the car noticeable mainly on motorway. The vibration is enoying and spoiled the ride. It make the satnav vibrate for example
I feel the vibration with my feet, not through the steering wheel and not through the seat.
The intensity and frequency of the vibration are the same when doing 60mph or 80mph but the intensity seems to be greater when accelerating.
During the last service the front wishbone link near side and off side where changed.
I am wondering if the upper front and rear link should have been changed at the same time.
Would a worn front and rear link could cause a vibration which shake the front of the car?
Is there a way of checking if the links have abnormal play in them?
Thank you for your help
Jack
Hi thank you for your answer
113K miles last service in February 2009.
Front tyres are more or less new, the front where change around March 09 which was bout 10K to 12K miles ago.
If it was the disk the amplitude of the vibration should increase with speed and I should feel it when braking.
But it is not the case.
It is a very strange vibration and I would really like to cure it.
Jack
113K miles last service in February 2009.
Front tyres are more or less new, the front where change around March 09 which was bout 10K to 12K miles ago.
If it was the disk the amplitude of the vibration should increase with speed and I should feel it when braking.
But it is not the case.
It is a very strange vibration and I would really like to cure it.
Jack
Edited by Jack_and_MLE on Friday 18th September 12:10
Sorry few more details
It is FWD car
I did swap the wheel round and it did reduced the vibration for a while. What was discovered at the time was the front near side alloy was not round this is why I have a new alloy at the front.
I cannot discern if the vibration are coming from the near side of the off side.
The back tyres are 2 weeks old.
No noise just this annoying vibration
Jack
It is FWD car
I did swap the wheel round and it did reduced the vibration for a while. What was discovered at the time was the front near side alloy was not round this is why I have a new alloy at the front.
I cannot discern if the vibration are coming from the near side of the off side.
The back tyres are 2 weeks old.
No noise just this annoying vibration
Jack
You definitely cant get it just holding the engine revs up while stationary???
I'm thinking flywheel. You would feel that with your feet.
Have had the much less common "inner" C.V joints cause similar things.
!!!!BUT!!! 99% of vibration issues are caused by wheels and tyres, and or there balance.
You really need a "known good" set of wheels to swap to and try before you spend money on suspension arms, C.V joints, flywheels etc.
I'm thinking flywheel. You would feel that with your feet.
Have had the much less common "inner" C.V joints cause similar things.
!!!!BUT!!! 99% of vibration issues are caused by wheels and tyres, and or there balance.
You really need a "known good" set of wheels to swap to and try before you spend money on suspension arms, C.V joints, flywheels etc.
Edited by Tame Technician on Friday 18th September 19:58
It's a CVT gear box! so no flywheel.
Can you correct me if I'm wrong, if it was a wheel/tyres issue I shouldn't I feel it through the steering wheel?
I am getting confused now!
No not stationary, I'm use the cruise control quite a lot which is easy to keep a constant speed with.
TT what would be the consequence of driving with worn foward and back upper suspension arms?
Jack
Can you correct me if I'm wrong, if it was a wheel/tyres issue I shouldn't I feel it through the steering wheel?
I am getting confused now!
No not stationary, I'm use the cruise control quite a lot which is easy to keep a constant speed with.
TT what would be the consequence of driving with worn foward and back upper suspension arms?
Jack
CVT!!!! With a 2.5TDI, thats not good. Those gearboxes can be all sorts of trouble, could even be that causing the problem, although they tend to vibrate at 40mph not 80.
And they do have a flywheel, Big heavy dual mass thing just like a manual, just doesn't have a clutch bolted to it.
The fact that you feel it through your feet and not the steering wheels suggest its not the front wheels and infact its the rear wheels. But the fact that you dont get it through the seat suggests, its not the rear wheels so its something else at the front. Whats at the front and isnt the wheels or rotating at wheel speed. The engine and gearbox. SO engine mounts and flywheel are the most likely cause of a vibration there. But I would have expect you to get it when reving the engine and you dont. SO that leads me back to gearbox or drive shafts/C.V joints again.
Regarding suspension arms.
If the upper suspention arms are worn, and it usually the ball joint on them that wear, you tend to get vague steering and unusually tyre wear, maybe some knocking over bumps too.
Not sure which arms you had replaced, We referrer to the lower arms as bent arm and straight arm. Bent one is front most, straight one rear most. Other wise your get drawn into saying front and rear, and then people get confuse cos you say rear wishbone, but still meant the front of the car etc.
You dont have to replace the straight arm when the bent one is done.
Older cars, especially S4's, can have the handling and steering feel dramatically improved by replacing both the upper arms and both the lower ones on each side. Basically is a tiny amount of play (undetectable by usual test) in each ball joint, and that bit of play in each of the joints adds up to enough to make the steering feel rubbish. Replacing them all at once transforms the car.
All that said, I've never fixed a vibration by changing arms.
And they do have a flywheel, Big heavy dual mass thing just like a manual, just doesn't have a clutch bolted to it.
The fact that you feel it through your feet and not the steering wheels suggest its not the front wheels and infact its the rear wheels. But the fact that you dont get it through the seat suggests, its not the rear wheels so its something else at the front. Whats at the front and isnt the wheels or rotating at wheel speed. The engine and gearbox. SO engine mounts and flywheel are the most likely cause of a vibration there. But I would have expect you to get it when reving the engine and you dont. SO that leads me back to gearbox or drive shafts/C.V joints again.
Regarding suspension arms.
If the upper suspention arms are worn, and it usually the ball joint on them that wear, you tend to get vague steering and unusually tyre wear, maybe some knocking over bumps too.
Not sure which arms you had replaced, We referrer to the lower arms as bent arm and straight arm. Bent one is front most, straight one rear most. Other wise your get drawn into saying front and rear, and then people get confuse cos you say rear wishbone, but still meant the front of the car etc.
You dont have to replace the straight arm when the bent one is done.
Older cars, especially S4's, can have the handling and steering feel dramatically improved by replacing both the upper arms and both the lower ones on each side. Basically is a tiny amount of play (undetectable by usual test) in each ball joint, and that bit of play in each of the joints adds up to enough to make the steering feel rubbish. Replacing them all at once transforms the car.
All that said, I've never fixed a vibration by changing arms.
Fixing this is gonna be tricky, and to be fair on a car that old Buying new wheels and tyres and things could all be a waste of money. Given its a 2.5TDI with a multi tronic gearbox I would advise you get rid of it even if it didnt have a vibration. Sorry to be harsh but that what I think of them.
If you are determined to get to the bottom of it however......
What we do in these situations, is swap wheels from our loan cars, because they are "known good". New ones, while you know they are perfectly round, are not so good for testing, because if its your tyre fitters balancing machine out of calibration and you get two new wheels and ask him to put two tyres on them, you could still have a vibration for the same reason even with different wheels. If you drive loan Car B at the same speed and its fine, and but car B's wheels and tyres on customer X's car and there is no improvement, you know its not wheels+tyres, Fact no arguments.
If you get two wheels and tyres off ebay, or you get some new ones, how do you know the balance is right on them. The number of people that complain of vibration after having tyres fitted, because a weight fell off or they didnt get done right for whatever reason.
Although its "unlikely" to be front wheels as you cant feel it through the steering wheel, as you don't get the vibration when you are not moving and holding the engine at the same revs, it "could" still be wheel related (front or rear), as that is nearly always the problem with any vibrations at speed.
Any wheel refurber should be able to check if the wheels are round, but usually you can do it by eye, look at the inside edge of the rim while rotating the wheel.
If you can get a "known good" set of wheels to try and it makes no difference then it most probably drive line.
Now idea where you would get the wheels apart from an Audi centre, sorry.
If you are determined to get to the bottom of it however......
What we do in these situations, is swap wheels from our loan cars, because they are "known good". New ones, while you know they are perfectly round, are not so good for testing, because if its your tyre fitters balancing machine out of calibration and you get two new wheels and ask him to put two tyres on them, you could still have a vibration for the same reason even with different wheels. If you drive loan Car B at the same speed and its fine, and but car B's wheels and tyres on customer X's car and there is no improvement, you know its not wheels+tyres, Fact no arguments.
If you get two wheels and tyres off ebay, or you get some new ones, how do you know the balance is right on them. The number of people that complain of vibration after having tyres fitted, because a weight fell off or they didnt get done right for whatever reason.
Although its "unlikely" to be front wheels as you cant feel it through the steering wheel, as you don't get the vibration when you are not moving and holding the engine at the same revs, it "could" still be wheel related (front or rear), as that is nearly always the problem with any vibrations at speed.
Any wheel refurber should be able to check if the wheels are round, but usually you can do it by eye, look at the inside edge of the rim while rotating the wheel.
If you can get a "known good" set of wheels to try and it makes no difference then it most probably drive line.
Now idea where you would get the wheels apart from an Audi centre, sorry.
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