I'm hoping someone can point me in the right direction please? My Octavia is making an unfamiliar noise from the front passenger corner, but only when I am turning right and have some throttle. If I eg coast around the corner or roundabout then it doesn't make the noise.

 

The noise is a little hard for me to describe, it sounds like it is creaky. Not like a spring, and it isn't a grinding/knocking/rattling.

 

I'm thinking strut top mount? But I'm not familiar with the symptoms or noises this may cause so wanted to get some advice before just trying to dive in...

Does it sound like knuckles cracking?  If so, suspect your CV joint.  A quick look to see if the protective boot is damaged will help.

 

Hmm, not so much a cracking, it sounds more creaky. I'll see if I can get a recording of it, not sure how well it'll pick up though.

Dry or worn roll bar bushes?, can you reproduce the noise by pushing the suspension up and down while parked?.

Can't reproduce it when the car is parked. I took it out just now and managed to record the noise it makes, you can hear it here, at about 7 seconds in when I pull out of a junction and again at about 18 seconds

 

 

CV joint?

Edited 18 October, 20205 yr by abo

Assuming that we are both talking about the resonating light tap at 7 and 18 secs, have a look at your exhaust centre support mounts in the cross member and front pipe mounts onto the subframe.

 

The support irons on the exhaust itself can rot through and break free leaving the support postioned lovely into the rubber mounts, but not actually attached to the actual exhaust pipe as the weld has failed.

 

You can test a cv joint, by finding an empty carpark, and doing circles both left and right on ful lock. If the joint is faulty, it will rattle and chatter a bit like an old fashioned football rattle.

The speed of the rattle will vary depending on which wheel is turning the tightest i.e., left turn, the n/s wheel turns a tighter circle than the o/s, so the o/s wheel rotates faster than the n/s. The reverse applies on right turns, hope it helps.

Edited 18 October, 20205 yr by kentphil1

I'll have a look at that when it isn't so wet, thanks. Exhaust is stainless, at least if that's the problem it has a lifetime guarantee iirc

Does the CV joint rattle regardless of which direction I'm turning? This is only happening when I'm turning right.

CV joints tend to knock more when placed under the most load when turning through the tightest angle.

 

To make this easier to visualise, imagine a group of soldiers maching in ranks, and the leader asks them to turn. the soldiers on the inside if they are turning right, tend to just mark time, whereas the soldiers on the outer ranks carry on marching at pace to make the turn.

 

In your case, the joint on the o/s/f is turning a tighter angle at a lower speed, while the n/s/f turns at a lesser angle and higher speed assisted by the diff, otherwise the inner tyre would destroy itself.

 

As has already been said, joints usually fail when the protective boot splits, but it is not unheard of a joint to fail just due to excess wear and tear.

 

Best plan is to jack the car up safely, use an axle stand to support the car just in case of movement, then put the steering on lock with the car switched off and rotate the wheel by hand while looking at the joint and boot to see if anything is not right under there.

 

Worn joint also tend to lock and release when rotated rather than smoothly rotate (difficult to explain, but you'll know it when you see it, it's that obvious).

 

Hope it helps, difficult subject to explain in a single post, good luck

Thanks, good to know! I'll have a look when it's not wet

Definitely the CV joint. I've finally got round to replacing it and the noise has gone. I had to remove the whole driveshaft in the end and grind the CV joint to get to the circlip. I got the shaft out by undoing the steering arm ball joint and three bolts to the bottom arm, and knocking the hub off the CV joint. Then the six bolts on the other end.

 

Slight problem now: the car pulls to the left under acceleration (the side with the dodgy CV). Everything screwed together ok, nuts and bolts are torqued to the settings as per Haynes. What could I have done wrong?

Doh, of course it'll need tracking, I tinkered with the bottom arm ball joint... 

Argh! Something is wrong somewhere, I took the car in for alignment just now and the problem is still there; still pulling left under throttle...

 

It feels like there is only drive on one side, is it possible I've e.g. popped or otherwise shagged the inner CV when I've been messing about or something?

Hi Abo, unless your Octavia had a LSD fitted (almost certainly not in a TDI unless fitted later) you shouldn't get any drive at all if drive was lost to one side. Is the place that checked your alignment well known?

Could be they got it wrong. Local company, literally just down the road from me. They've been there 40-odd years and I've used them for various reasons in the past but maybe not for an alignment. I lowered the car about five years ago and got it aligned at a different place (and they did a good job), I reckon I'll pop in there tomorrow and get a second opinion...

I had that after removing the hub, I had not retightened properly one of the wishbone (I think) securing bolts, long time ago but the torque steer was unnerving, bolt tightened and all was well.

 

Check everything that you released but particularly the wishbone mountings, I will stick my neck out and say it is the front one as that would move forward under acceleration.

Don’t out rule tyres and the road just in case.

14 hours ago, DeanVRS20VT said:

Don’t out rule tyres and the road just in case.

 

Hopefully not the case, the car was spot on before I did it (CV aside)

Just googling some more... I followed the procedure in Haynes for tightening the hub nut which matches what I've read on the internet for the 12 point hub nut. People seem to be suggesting things are different for a hex nut which is what came with my new CV joint, but I cannot find consistent information for it, just a variety of torque numbers for the vehicle on and off the ground, and some Bentley procedure.

 

Is this the case, if it is, then could this be the issue, and what is the correct procedure for torquing a hex hub nut?

well...  stuoid question... is the new cv joint definitely the correct one?

if it isnt, it may be creating a different ratio of drive to the wheel?

28 minutes ago, mac11irl said:

well...  stuoid question... is the new cv joint definitely the correct one?

if it isnt, it may be creating a different ratio of drive to the wheel?

 

I assumed so when I bought it  I've been using the place for 30 years and never had a problem (LT Motors in Stockton). Joint is a Shaftec CV351N which is suitable according to the compatability list here https://www.ebay.co.uk/itm/193465607960 

Update: I decided to buy a couple of spare 12 point nuts, they arrived on Friday. Fitted one yesterday, torqued as per Haynes and it is *much* better. Still pulls a little under heavy throttle, I'm putting it down to either the nasty tyre on that side (will be replacing the fronts shortly) or possibly my torque wrench not being 100%