Mystery front end knock (clunk) 306

I agree...you need to be systematic. Get a driver and as a passenger poke your head around the car. Establish which types of situation it makes the clunk in, and repeat that again and again.
 
No, not inside. Listen from outside. It shouldn't need any speed if it's suspension related.

Outside noises that need speed are best listened to when driving parallel to a wall. The bigger the wall the better reflection of sound. Reflects the noise so well back at you it will appear amplified and you will know immediately when the noise is on the side with the wall.
 
Last edited:
I agree...you need to be systematic. Get a driver and as a passenger poke your head around the car. Establish which types of situation it makes the clunk in, and repeat that again and again.
A few of us have reported similar issues with GTi6's. I could repeat the noise mine made easily - downhill, left hand, rapid progression. Still never made it easier to locate.

Cheers

Justi
 
Could it be body related? Some bracing behind the dash? Flex in the firewall?
 
^ That reminds me of the mysterious 504 / 505 clunk people used to get.
The front cross member was bolted to the chassis rails and as the rails in 504s and 505s were soft (for collapsability in the crumple zone), a slight clunk used to develop.

Tightening the bolts had to be done carefully as it was quite easy for a heavy-handed mechanic to crush the chassis rails a bit more than desirable.

Told to me by J.P, a Pug mechanic who had forearms like the skipper in Gilligans Island.:rolleyes: and who learnt all that the hard way.
 
I am sure the problem is solvable but a pain to pinpoint and because it is only annoying but not vital most people give up and box it with "they all do that". Nothing wrong with that but I would make sure it is not vital first.
 
I am sure the problem is solvable but a pain to pinpoint and because it is only annoying but not vital most people give up and box it with "they all do that". Nothing wrong with that but I would make sure it is not vital first.
Exactly this, I don't want to give up as I don't want to be driving around with something catastrophic ready to happen. I also wouldn't want to sell the car with the noise unsolved. The sagging door card fabric I can deal with... They all do this. But that's hardly going to cause an accident is it.
 
You know what? Is it possible it may be wear in the rack? Have you checked this? The idea came to me whilst reading another thread about adjusting the rack/pinion backlash to take up wear. The pinion and rack wear and eventually at full lock there is enough slop that the rack will reposition itself giving you the clunk. Bad news is you might have to take the steering off to check. With the steering on, you won't be able to see the slop because the weight of the car works against you. You might be able to get away with disconnecting the tie rods at the hubs and giving them a wiggle up and down at full lock but to be 100% sure you really need the rack on the bench. Maybe test in car first and if not clear, take to bench. If slop is clear you will have to take the rack off to shim/fix it anyway, so your call.
 
You know what? Is it possible it may be wear in the rack? Have you checked this? The idea came to me whilst reading another thread about adjusting the rack/pinion backlash to take up wear. The pinion and rack wear and eventually at full lock there is enough slop that the rack will reposition itself giving you the clunk. Bad news is you might have to take the steering off to check. With the steering on, you won't be able to see the slop because the weight of the car works against you. You might be able to get away with disconnecting the tie rods at the hubs and giving them a wiggle up and down at full lock but to be 100% sure you really need the rack on the bench. Maybe test in car first and if not clear, take to bench. If slop is clear you will have to take the rack off to shim/fix it anyway, so your call.
Found a strange coincidence today.
I’ve just picked up a 1999 N5 Cabrilet. I drive it back from Victoria Point to the Gold Coast on a permit. The car handled like a dog and had a slight knock. It had very bad torque steer causing a veer to the right on acceleration.
Jacked it up and put it on stands today and found the incorrect (undersized) ball joint fitted to the LH side.
I don’t know how whoever did this failed to notice! I could shake the tyre and see 15-20mm of free play at the front of the tyre. I could also see the ball joint pin moving about in the retaining hole.
I suppose this proves it can be done but I think you would need to be vision and sensory impaired not to notice before lowering the car and it would be glaringly obvious on the post repair test drive.
 
Found a strange coincidence today.
I’ve just picked up a 1999 N5 Cabrilet. I drive it back from Victoria Point to the Gold Coast on a permit. The car handled like a dog and had a slight knock. It had very bad torque steer causing a veer to the right on acceleration.
Jacked it up and put it on stands today and found the incorrect (undersized) ball joint fitted to the LH side.
I don’t know how whoever did this failed to notice! I could shake the tyre and see 15-20mm of free play at the front of the tyre. I could also see the ball joint pin moving about in the retaining hole.
I suppose this proves it can be done but I think you would need to be vision and sensory impaired not to notice before lowering the car and it would be glaringly obvious on the post repair test drive.
Just sorted the problem with the Cabrilet.
It turned it to be the ball joint was left loose (horizontal retaining bolt) obviously expanded the receiver hole and caused all the free play and rattling. I ended up replacing the ball joint anyway. It now has no knock and no play.💪🏻
 
Found a strange coincidence today.
I’ve just picked up a 1999 N5 Cabrilet. I drive it back from Victoria Point to the Gold Coast on a permit. The car handled like a dog and had a slight knock. It had very bad torque steer causing a veer to the right on acceleration.
Jacked it up and put it on stands today and found the incorrect (undersized) ball joint fitted to the LH side.
I don’t know how whoever did this failed to notice! I could shake the tyre and see 15-20mm of free play at the front of the tyre. I could also see the ball joint pin moving about in the retaining hole.
I suppose this proves it can be done but I think you would need to be vision and sensory impaired not to notice before lowering the car and it would be glaringly obvious on the post repair test drive.
Yep - I would have thought that impossible. They're a very different size. :(

Cheers

Justin
 
HI, me again! Guess what? The sound has transformed from a dulled knock to a metallic CRACK! And now persistent. Turning left, right, going over transverse road joins etc. Car still drives fine. But, I'll be taking her off the road and parking it in the workshop - my mechanic won't be too happy given the hours he's put in helping me diagnose this. I'm going to as for the engine mount to be completely removed again for another check. Then I'm going to get the gear box mount looked at (the sound could be linkages slapping on something?) and the steering rack. I'm actually frustrated now - I love the car, maintain it well. I will sell it at some point but I can't sell a car with an issue. If my current mechanic can't find the problem I'll have to throw an Aussiefrogs "diagnose my noise" BBQ in LCNP like the old days....
 
I had a subaru outback that had seized its front left wheel (hub ?) bearing. The noise was indistinct and occasional. Ranged from clicking to a noticeable grinding. Actual driving characteristics were unchanged. Became very apparent when stripped down........

Just maybe.....as an aside there was no detectable play in the wheel either.
 
Well, should be easier to diagnose now, at least.

Have you tried to just push the front of the car down by hand to replicate the noise? Should help with locating which side of the car it comes from?
 
HI, me again! Guess what? The sound has transformed from a dulled knock to a metallic CRACK! And now persistent. Turning left, right, going over transverse road joins etc.
My 306 also has an intermittent crack sound turning left, right, etc. Taking out the parcel shelf and/or fold down rear seats allowed the crack to echo a bit and I then traced it to play in the rear trailing arm bearings as I can pull on the wheel and see the movement.
 
My 306 also has an intermittent crack sound turning left, right, etc. Taking out the parcel shelf and/or fold down rear seats allowed the crack to echo a bit and I then traced it to play in the rear trailing arm bearings as I can pull on the wheel and see the movement.
Hi Alex, I will have a look but I'm fairly certain it's from the front end. I have a theory that when I had the new struts and top mounts installed that maybe the springs are not set in the correct position on the base plate. I don't know how they should be set, I trust the mechanic for that but who knows - I have to pull some things apart I think.
 
Good luck to you, fitted xsara vts suspension to mine got rid of all of this.
 
Firmer, more direct and stiffer all round, still handle speed bumps very well. Good thing to do, it lowered the front considerably which is a pain to get the jack under now, small issue. So struts, sway bar and rear end. Dimensionally identical.
 
Hi everybody
I had a knock in the front end too. I replaced everything in the suspension but was still there. Engine and gearbox mounts looked ok to me. I eventually took it to Alpine Affair and they found that the gearbox mount had cracked. It’s a common problem. They welded a big washer in to fix it.
It fixed the knock! Definitely check this out. It drove me crazy for ages.

Now though I have another that happens over bumps. Sounds like something is lose. Argh!!!!
 
Top