Rear Knocking/rattle What Could It Be?

[czmate1999]

Okay, good news. Dropped it back to the garage on the 2nd Aug - as mentioned above - and got it back on the 7th. have driven nearly 2.5k miles and, so far, it’s been good as good. Just looked at the garage write up and they mention a couple of codes, see below.

‘Customer complained of jolting coming from rear of vehicle, got vehicle into the workshop and tested and confirmed customers complaint, c/o guided found no faults related but found tpi 2049497/3 related requires kit (0CQ.598.305) AND (G.060.175.S0) and tpi to be followed further (warranty)’.

Can anyone elaborate on the codes in red?

Cheers.

 

[czmate1999]

Any thoughts on those codes?

 

[Chippy1970]

I've had an annoying knocking from mine lately. One morning I went out drove off and there was a constant knock in time with the speed. Pressed the brakes a few times and it stopped. Like the calipers were loose or rattling.

Not great on a 3 year old van

 

[Sparkyis]

So…… I have followed this thread as I have an annoying knocking sound after a sharp bump e.g. rolling over a drain or pothole on the near side rear.
Van is a 2017 T32 LWB 204 DSG.
Remedies attempted as follows:
- Tailgate new bumper stoppers and adjusted- no noise from this
- Rear rubber lower spring seats replaced with uprated equivalents- I really hoped it would be this but no improvement.
- Upper seats checked at the same time along with springs.
- Rear shocks replaced with as new VW correct part number shocks even though van had gone through NI MOT with no issues a few weeks ago- no solution despite the shock looking awful!
- Spare wheel carrier rattle tested and LOTS of foam added to the hinge area, strap carrying the wheel and above where the wheel could potentially hit the plastic chassis trim- no joy here.
- Rear brake dismantled, pad retaining springs pinched tighter with pliers and all got a layer of copper grease- not a bit of difference (I did not get knock disappearing on braking but thought it was worth a try…)
- Removed Jack from mounting point on rear arch, drove, sound still present so put it back.
- All undertrays and heat shields have been checked.

So there we are! I can only describe it as a harsh jolt/ knock after the rear wheels hit a bump like pothole. My next thoughts are further getting the wife to drive me around whilst I try to pinpoint it!

Rear outer ARB bushes looked fine when I removed them to replace spring seats but thinking about replacing outer and inner bushings as next low cost possibility before moving on to swingarm bushings…

Anyone any other suggestions?

At least I have new rear spring cups and shocks

 

[Sparkyis]

My problem is solved! (Almost!)

Even though my better half is convinced it’s boxes jumping in the back which it’s not ’cos I’ve driven without them and the knock’s still there, I decided to next look at the rear ARB bushings before the swingarm bushings because taking that off in the driveway terrifies me. Being a cheapskate I ordered a set of outer and inner bushings from PSB because they are half the price of powerflex which I really want and red is almost as cool as purple

As soon as I disconnected both sides of the outer bushing mounts I could immediately rock the bar and hear the very obvious “clunk“ where the bar hits metal due to the mostly perished inner near side bushing!!! Can’t believe I didn’t try checking the bar when I replaced either spring seats or shocks but there you go, live and learn!

Now I’m just waiting for a large enough spline set to arrive so I can unbolt the inner bushing mounts, starting with the offending one as the other side has the LED self- levelling bracket attached and I want to see how easy the bolts come out before I get to the more complicated side.

So….if you have a knock from the rear going over potholes etc. and can’t figure out what it is and have tried spring seats, spare carrier, shocks, brake pad springs then give the ARB bushings a try!