Octy 4x4 which clicks but only when under light load such as uphill or gentle acceleration

Doesn't do it on overrun or hard acceleration

Edited 15 April, 201214 yr by karlbar2k

Link works now

Sounds a little like a brake discs, Have you inspected the condition of your brakes? Brake discs can can sort of rot on the outer edge and as the dic becomes thinner where the pads make contact it creates a lip wich can catch on the caliper, have a look at your discs and if they do have a lip on the outer edge you can tap it off with a hammer

Discs are relatively new so no lip to speak of.

Like I said in the OP it only makes a noise when the engine is lightly loaded. If you boot it then no noise?

Edited 15 April, 201214 yr by karlbar2k

Bump for someone techie to have a listen and advise, pretty please!

Sounds a bit like the tap of a nail or stone in a tyre, but then it would probably be all the time!

Is it coming from behind the dash? Could be a relay somewhere?

Not a relay as sound is definitely outside, load dependant and quieter with the windows shut.

Is definitely associated to a speed related rotating part. So something on a wheel, disc, shaft, prop etc but can't replicate with wheels off ground and no load on engine

Update:

I tried one click of the handbrake this morning and the noise went away. Further to this I pulled fuse 31 for the rear haldex and no more noise so it's ruled out the brakes as the source.

Now I need to get the haldex oil and filter changed before testing again. Could either be the haldex itself or the rear driveshafts when under load. The noise is worse on the passenger side as I had mechanic listen to drive by a few times, so I am hoping it is the rear passenger driveshaft joints and not the haldex unit.

Bloody car is trying to bankrupt me and with my kids helping as well I don't stand a chance

Ouch :( hope its not the haldex mate. I was seriously considering a mk1 4x4 estate as my next car after the Feli but haldex reliability and the cost of fixing it is the main worry for me.

I had the same worries when I was looking for the octy in the beginning. But there are very few horror stories about haldex out there which is why I have had so much fun trying to diagnose this. I have just picked up a filter as I already have the oil as it is due a change (overdue:D)so first thing to do is drain the diff and see what it's like. Then looking at drive shaft joints or did find one guy that had a worn donut

The only real horrors I have found relate to US main dealers using standard diff oil instead of proper haldex oil causing all sorts of diff explosions/implosions

If it is your Haldex unit fecked, don't bother fixing, just replace

TT haldex

another

OK

preliminary results having just picked the car up and driving home. Car is not making clicking noise any more? Yet?

list of what was done:

Haldex oil changed

Diff oil changed as well (drained the wrong plug for the haldex so ended up doing both )

checked the driveshafts and no play?

both rear wheel bearings changed (what a PITA that was) 13ton to press the shaft out of the hub?

(This involved stripping out the full trailing arms to be able to get it on the press)

as pretty much all the nuts and bolts etc have been removed/replaced not sure what the fix was but logic tells me wheel bearings or haldex oil? leaning toward wheel bearings though.

Also had:

Cambelt and tensioner and waterpump

oil and filter

driveshaft boot on the front nearside

Other job while it was in was to swap the front subframe out. Didn't go to plan as the TT/Cupra/S3 ball joints fouled the driveshafts? Was going to swap the existing arms onto the new subframe as a part fix but the bolts were well seized so it got abandoned and the original put back on for now. ALTHOUGH it has now gone quite what should have been the process for the TT arms? as the existing balljoints seem to have size 8 bolts and the tt ones 10's ?

Jesus you've been busy! That's a pretty serious list of jobs there!

My money's on a rear wheel bearing. I had a similar noise on my old car and was convinced it was the rear diff. I even went as far as buying a replacement used rear diff, which was very hard to find. When it came to stripping down the rear axle to change the diff, I discoved that one of the rear bearings was a complete mess! Slightly annoying, but made worse by the fact I did it on a weekend and didn't have any new bearings to hand!

biggest problem was getting the shafts out of the hub. thought the press was going to go bang at one point