Banging at the front when accelerating and hitting a pot hole.

[roaddetective]

Hi all

Somebody must have had this problem in the past, so I thought I would pick a couple of your brains. It has really started to happen more since the remap, as the extra power seems to upset the car when accelerating and hitting a very rough surface. Get a pothole and there is sometimes a hard bang from the front of the car, usually on the near side. I think it's down to the average shock absorbers fitted to my Octavia VRS, details of car below. It just seems the shocks are either fully extending or compressing that is causing the bang. They can't manage the job they are meant to do. On my previous Octavia VRS, a 2011 fl model, I fitted Bilstein B8 shocks all round, which did a brilliant job of absorbing the bumps and uneven surfaces. Do I really need to spend on new  better quality shocks for a car that has only done 20k miles?  In normal driving you never get this problem, as the car is smooth and handles quite well. 

Edited 21 October, 2020 by roaddetective

[langers2k]

It's more likely to be the ESC/ESP system and wheel hop.

 

A quick google suggests a stiffer dogbone insert or better tyres help

 

https://www.golfmk7.com/forums/index.php?threads/banging-noise-while-spinning-tires.355534/

[roaddetective]

3 minutes ago, langers2k said:

It's more likely to be the ESC/ESP system and wheel hop.

 

A quick google suggests a stiffer dogbone insert or better tyres help

 

https://www.golfmk7.com/forums/index.php?threads/banging-noise-while-spinning-tires.355534/

Have heard about the dogbone insert, but got a little bit put off by the stories of vibration. As for the tyres, I have some great ones all round. Mitchelin PS4S, 235 /35/ 19. 

[langers2k]

Agreed, a side effect will be more vibration.

 

There's a pretty lengthy thread here: 

 

 

[roaddetective]

7 minutes ago, langers2k said:

Agreed, a side effect will be more vibration.

 

There's a pretty lengthy thread here: 

 

 

Thanks for this extra information. I have just read a few of the posts trying to get an accurate idea on whether to fit one, or not. Don't fancy any extra vibration, but don't like the odd time it bangs at the front. When it happens it feels like somebody is hitting the underneath of the car with a sledge hammer. Never get the bang when accelerating hard on most surfaces, even when I get the odd flash of the traction control light, it's just when the car hits a bad uneven surface it happens. Only happened 4 times in the last 3-4 months, so not too bad I guess. 

[Ads230]

 

17 hours ago, roaddetective said:

Never get the bang when accelerating hard on most surfaces, even when I get the odd flash of the traction control light, it's just when the car hits a bad uneven surface it happens.

 

Doesn't sound like it's the lower engine mount in your case, then - seems more likely (as you've highlighted) that it's suspension related (i.e. hitting bump stops) OR heatshields OR exhaust hangers that meet their tolerance limit and connect with something... 

 

If it only happens occasionally under certain conditions, theoretically it would be easier to nail down - except it's hard to repeat those conditions without nailing the car a lot.

 

As an aside, replacing the lower mount is an excellent mod (particularly in a FWD car with upwards of 260bhp) and IMHO the additional NVH is minimal in the TSI's. That said, everyone's taste is different and I'm aware the 'tuners' have got a bigger appetite for NVH than others. Considering the parts are ~£50 and easy to fit, it's 100% possible to try and rollback if it's not for you.

[roaddetective]

1 hour ago, Ads230 said:

 

 

Doesn't sound like it's the lower engine mount in your case, then - seems more likely (as you've highlighted) that it's suspension related (i.e. hitting bump stops) OR heatshields OR exhaust hangers that meet their tolerance limit and connect with something... 

 

If it only happens occasionally under certain conditions, theoretically it would be easier to nail down - except it's hard to repeat those conditions without nailing the car a lot.

 

As an aside, replacing the lower mount is an excellent mod (particularly in a FWD car with upwards of 260bhp) and IMHO the additional NVH is minimal in the TSI's. That said, everyone's taste is different and I'm aware the 'tuners' have got a bigger appetite for NVH than others. Considering the parts are ~£50 and easy to fit, it's 100% possible to try and rollback if it's not for you.

Hi Ads 230

I have just had the car up on the jack and can see no problems. Not even a weep from the shock. It does not sound like heatshield, or even exhaust hitting something noise. Too much of a solid bang. I am also at this moment looking at fitting the Dogbone mount, just deciding which one to use that will give the least vibration. 

[langers2k]

I think the 'softest' is probably the Powerflex red as it's designed for diesels. Next level is probably the Powerflex yellow. I expect either should be fine on a road car based on other peoples posts. It seems you're most likely to notice the vibrations in reverse.

 

Then you're on to the harder versions, ie Powerflex purple/black or even the APR billet steel version.

 

Be interesting to see what you decide on and how you like it as I've noticed in wet conditions mine can get a bit bangy as traction disappears.

[roaddetective]

6 minutes ago, langers2k said:

I think the 'softest' is probably the Powerflex red as it's designed for diesels. Next level is probably the Powerflex yellow. I expect either should be fine on a road car based on other peoples posts. It seems you're most likely to notice the vibrations in reverse.

 

Then you're on to the harder versions, ie Powerflex purple/black or even the APR billet steel version.

 

Be interesting to see what you decide on and how you like it as I've noticed in wet conditions mine can get a bit bangy as traction disappears.

Yes mate once fitted I will post which one I went for and how it effects the car. I also read a long series of posts on the subject and was leaning towards the yellow. 

[banksie]

Don’t fit one! The car vibrates at idle and even more when your reversing. It does stop the wheel hop under acceleration, but the times that happens compared to the constant vibration just aren’t worth it. 
 

I fitted a yellow one to mine and the thumps on the suspension got worse. I’ve fitted VWR/Racingline shocks to mine 6 months ago, with the Powerflex, they made no difference!  I took the Powerflex off and the car was a lot better. Unfortunately the car is going to have to be sold soon, so the shocks and HR spring are coming off as Webuyanycar don’t want it with them on! Oh and the Scorpion rear exhaust will be off as well if anyone wants one! 

 

 

[roaddetective]

11 hours ago, banksie said:

Don’t fit one! The car vibrates at idle and even more when your reversing. It does stop the wheel hop under acceleration, but the times that happens compared to the constant vibration just aren’t worth it. 
 

I fitted a yellow one to mine and the thumps on the suspension got worse. I’ve fitted VWR/Racingline shocks to mine 6 months ago, with the Powerflex, they made no difference!  I took the Powerflex off and the car was a lot better. Unfortunately the car is going to have to be sold soon, so the shocks and HR spring are coming off as Webuyanycar don’t want it with them on! Oh and the Scorpion rear exhaust will be off as well if anyone wants one! 

 

 

Hi banksie.   Reading your post has got me thinking. Is the vibration at idle that bad it drove you mad, so to speak.  The thing that has been a worry to me is the odd time it really bangs underneath when accelerating and hitting an uneven surface. It's like a sledge hammer hitting the chassis of the car. Feels like it's going to damage something. Should I put up with the odd bang, or put up with vibration at idle with the dogbone fitted? 

[banksie]

3 hours ago, roaddetective said:

Hi banksie.   Reading your post has got me thinking. Is the vibration at idle that bad it drove you mad, so to speak.  The thing that has been a worry to me is the odd time it really bangs underneath when accelerating and hitting an uneven surface. It's like a sledge hammer hitting the chassis of the car. Feels like it's going to damage something. Should I put up with the odd bang, or put up with vibration at idle with the dogbone fitted? 

It is both! At idle it’s worse than a diesel! On the road having had the suspension fitted it became apparent that if you hit a ridge in the road there was a loud bang as you suggest. I had a mate put it up on his ramp and we checked everything over to make sure nothing was loose and it wasn’t. So I rang the suspension specialist who put the kit on and it was booked back in to check it over again. I then had the thought that it might be the Powerflex as it’s supposed to make the front end “stiffer”, so I removed it. Sure enough the banging stopped!

Edited 24 October, 2020 by banksie

[roaddetective]

30 minutes ago, banksie said:

It is both! At idle it’s worse than a diesel! On the road having had the suspension fitted it became apparent that if you hit a ridge in the road there was a loud bang as you suggest. I had a mate put it up on his ramp and we checked everything over to make sure nothing was loose and it wasn’t. So I rang the suspension specialist who put the kit on and it was booked back in to check it over again. I then had the thought that it might be the Powerflex as it’s supposed to make the front end “stiffer”, so I removed it. Sure enough the banging stopped!

So if I understand your post, you had the banging going over a ridge in the road, was that when you were accelerating hard as in my case? Going over ridges taking it steady is not a problem at all. If you were also getting this banging over ridges with the Powerflex insert fitted and I am getting it with a standard insert, there is no cure!

[banksie]

Standard suspension/No Powerflex/No bang

Standard suspension/Powerflex/No bang (vibration at idle and generally makes the car less pleasing to be inside)

Modified suspension/Powerflex/Bang

Modified suspension/NO Powerflex/No bang

 

The bang with the Powerflex going over ridges was very bad. I actually went back to have a look as I thought I’d missed a pothole about 4 inches deep and the wheel would be bent, but it was basically just a slight ridge with overbanding!

 

I don’t know what to say if yours is doing it with standard suspension and no Powerflex? Tyres/tyre pressures?

Edited 24 October, 2020 by banksie

[roaddetective]

4 minutes ago, banksie said:

Standard suspension/No Powerflex/No bang

Standard suspension/Powerflex/No bang (vibration at idle and generally makes the car less pleasing to be inside)

Modified suspension/Powerflex/Bang

Modified suspension/NO Powerflex/No bang

 

The bang with the Powerflex going over ridges was very bad. I actually went back to have a look as I thought I’d missed a pothole about 4 inches deep and the wheel would be bent, but it was basically just a slight ridge with overbanding!

 

I don’t know what to say if yours is doing it with standard suspension and no Powerflex? Tyres/tyre pressures?

I know it's very odd. Tyres are nearly new Mitchelin PS4S and the pressures are spot on. I think I will book it into Skoda for them to have a look. 

[nidza]

This thread is too long, as described behavior looks as 1 to 1 for strong FWD car with an e-LSD assistance (XDS+ trademark in VAG) when momentum transfer balance between front axles is severely disturbed, what exactly occurs when one of the wheels loses traction on bump. I can provocate it in my car all the time, even it has VAQ in the front - because on high accelerations on low speeds, momentum difference between front half-axles can go above what VAQ can transfer. XDS+ in this case applies braking force to the slipping wheel with short braking bursts. 

 

edit: don't waste your life going to the dealers, all what's happening is perfectly normal. 

Edited 24 October, 2020 by nidza

[roaddetective]

50 minutes ago, nidza said:

This thread is too long, as described behavior looks as 1 to 1 for strong FWD car with an e-LSD assistance (XDS+ trademark in VAG) when momentum transfer balance between front axles is severely disturbed, what exactly occurs when one of the wheels loses traction on bump. I can provocate it in my car all the time, even it has VAQ in the front - because on high accelerations on low speeds, momentum difference between front half-axles can go above what VAQ can transfer. XDS+ in this case applies braking force to the slipping wheel with short braking bursts. 

 

edit: don't waste your life going to the dealers, all what's happening is perfectly normal. 

I think you may be right with the dealers. The other strange thing is, my last car was another Octavia, that one was a 2011 MK2 FL TSI. I had that one mapped from 200bhp to 250bhp and never had this banging problem with that one when accelerating over an uneven surface. That is what is throwing me a bit. 

[nidza]

https://www.volkswagen-newsroom.com/en/electronic-differential-lock-xds-3943

 

[MarkyG82]

10 hours ago, banksie said:

Standard suspension/No Powerflex/No bang

Standard suspension/Powerflex/No bang (vibration at idle and generally makes the car less pleasing to be inside)

Modified suspension/Powerflex/Bang

Modified suspension/NO Powerflex/No bang

 

The bang with the Powerflex going over ridges was very bad. I actually went back to have a look as I thought I’d missed a pothole about 4 inches deep and the wheel would be bent, but it was basically just a slight ridge with overbanding!

 

I don’t know what to say if yours is doing it with standard suspension and no Powerflex? Tyres/tyre pressures?

 

I actually found the opposite. With a purple insert fitted it is much more controlled at the front end. With or without B6 and prokit springs. With the shock and spring upgrade it's even more controlled but much firmer.  Taking the insert out in the next few weeks when I swap to winter wheels so it'll be interesting to see what it's like with the suspension mods but standard dogbone.

 

Vibration is quite a lot though. I don't mind it but the family are not too fond. Mainly at idle.