Hi, yes this is the part I'm referring to. Ive put one layer of electrical tape across covering both sides (the angled sides only - V) and this improved, I'm adding another layer at the weekend and hopefully this will resolve the problem. Worthwhile using gumipflege on the rubbers too or similar to refresh them - perished rubbers wont help..
Knocking sound over uneven surfaces
- Thread starter stannie203
- Start date
stannie203
Member
Cool, I'll give that a go and the take it for a drive.
I have a feeling my issue could be slightly different (a car nerd at work reckons it's the top mount where the suspension fastens to the car).
However, there's no harm fixing other creaks / creaks before they become creaks!
I have a feeling my issue could be slightly different (a car nerd at work reckons it's the top mount where the suspension fastens to the car).
However, there's no harm fixing other creaks / creaks before they become creaks!
stannie203
Member
So, I've wrapped the 'spike' with a bit of tape and had a fettle elsewhere.
I was trying to use my camera to see what was going on inside the wheel arches. Then thought, how come I can do this easily on the passenger side, but not on the driver side. (rear)
Turns out, crudely using a tape measure, there's a 1in difference between the wheel arch to the inner edge of the tyre rim. It's 4.5in on the passenger side where I had a new spring fitted the other week, and 3.5in on the driver side (where the mechanic said he could see a spring had been fitted 'recently' - before I bought the car).
Looks like this is going to be the root of the knocking noise - any guesses as to what will cause this drop in height - before I send it packing to the local garage?!
Edited to add these questions:
- Could it be the new spring fitted a couple of weeks ago is a different length to the existing on the driver rear?
- Or that the previously fitted spring (pre my ownership) is the wrong spring size, and the new passenger rear is correct?
- Would this cause a knocking noise?!
Either way, this knocking sound on uneven roads has occurred since the new spring was put in.
I was trying to use my camera to see what was going on inside the wheel arches. Then thought, how come I can do this easily on the passenger side, but not on the driver side. (rear)
Turns out, crudely using a tape measure, there's a 1in difference between the wheel arch to the inner edge of the tyre rim. It's 4.5in on the passenger side where I had a new spring fitted the other week, and 3.5in on the driver side (where the mechanic said he could see a spring had been fitted 'recently' - before I bought the car).
Looks like this is going to be the root of the knocking noise - any guesses as to what will cause this drop in height - before I send it packing to the local garage?!
Edited to add these questions:
- Could it be the new spring fitted a couple of weeks ago is a different length to the existing on the driver rear?
- Or that the previously fitted spring (pre my ownership) is the wrong spring size, and the new passenger rear is correct?
- Would this cause a knocking noise?!
Either way, this knocking sound on uneven roads has occurred since the new spring was put in.
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john-e89 said:
Correct ..however the dampers are also different between MSport and ‘normal’..
One member here had a MSport spring inadvertently supplied instead of a stock ride height spring and the effect was very obvious visually and ride height wise..
Also springs sag with age and use which compounds any differences…
As I said could be many other factors too..
john-e89 said:
Only if they are both the same. If you lift one side by 10mm it will push the other side down by x amount, as the weight distribution will alter. So the difference in height will be 10 + x. I think!
OP. It could well be the lower side 'bottoming' due to the above.
I think Msport is 15mm lower than standard. I'd be quite happy to say that's not what's causing your knocking though.
Ah, fair enough.
The dampers may affect the ride height for at least two reasons…
The sports damper has a shorter stroke..so the maximum possible extension / compression is more limited..
Depending on where the spring is attached to the bottom pre load collar the spring rate of an incorrect spring may affect both preload and therefore ride height..
I’m not sure that both dampers have their bottom collars in exactly the same position relative to the bottom mount?
The sports damper has a shorter stroke..so the maximum possible extension / compression is more limited..
Depending on where the spring is attached to the bottom pre load collar the spring rate of an incorrect spring may affect both preload and therefore ride height..
I’m not sure that both dampers have their bottom collars in exactly the same position relative to the bottom mount?
If you fit a damper for an E89, beit M sport, standard, Ohlins, KW's etc, they have no influence on ride height. If I wind my KW's up to full hardness it doesn't jack the back of the car up to look like a dragster, same for if I set them to fill softness, it doesn't squat on the ground scraping the exhaust. It's stays the same height.
john-e89 said:
That maybe so on some of those dampers but not Ohlins R+T you can adjust the static ride height by at least 40mm if you so wish..
Ohlins suggests a ride height analogous to MSport ride height but you can vary it by quite a large amount. :tumbleweed:
I’ve changed them on mine by about 30mm at various times to see what effect they have on ride and handlimg.
https://world.ohlins.com/app/uploads/2015/02/MI_BMSMP50.pdf
Refers
So in the case of Ohlins they pitch the nose down by 5mm compared to a stock MSport setting.
Check your rear anti-roll bar links. Especially if you replaced the rear springs without disengaging the hand brake.
Are you sure the noise isn't coming from the rear roof clamshell hitting the rear deck. It should sit around 3mm off the black boomerang bit that sits on the top of the boot lid.
Are you sure the noise isn't coming from the rear roof clamshell hitting the rear deck. It should sit around 3mm off the black boomerang bit that sits on the top of the boot lid.
stannie203
Member
That's not a bad shout re the clam shell. When the weather has been cold and the car has a layer of frost on it I get a really distinctive noise coming from back there, as if it's creaking/scratching and breaking the ice as the shell moves.
And looking at the shell where it meets the rear of the car, there are two blobs (as if the paint has dropped and set) on either corner which takes that part of the shell much closer to the rear shelf. Could be that those are hitting?
Is there a way to adjust this gap to 3mm? But in doing so, is there a danger that the seal won't meet and water will get in?
And looking at the shell where it meets the rear of the car, there are two blobs (as if the paint has dropped and set) on either corner which takes that part of the shell much closer to the rear shelf. Could be that those are hitting?
Is there a way to adjust this gap to 3mm? But in doing so, is there a danger that the seal won't meet and water will get in?
