Mysterious front end clunk / knock (Video added)

[firefly1]

Hey everyone, a little problem I've been trying to diagnose but getting nowhere.

Currently running DG springs, H&R 26/22mm sway, Neuspeed dog bone mount. Used all new hardware during install and had this setup since 8k miles with no problem until now. I am now at 40k miles.

Symptoms: A single and light clunk / knock from the front of the car. Only happens when the driver side is disturbed either through small bumps or mild undulations in the road at moderate speed (20~30ish). Does not sound like subframe clunk, pushing hard into corners cannot replicate the noise.

Attempt: Replaced strut mount and strut bearing. Re-checked all bolts and all seems torqued to spec. Disconnected my end links today and the noise is still there. All other bushing seems ok visually.

Suggestions? Ideas?

 

[spiker369]

Interesting, this started happening to my car too not too long ago. But I'm bagged and my sound is coming from the passenger side.

 

[firefly1]

Interesting, this started happening to my car too not too long ago. But I'm bagged and my sound is coming from the passenger side.

Running out of idea on what to try next...

Ball joint? Possible but these rarely goes bad especially at 40k. And there's no noise when turning the wheel while driving or stopped.

LCA F/R bushing & mount: rear bushing seems ok visually. Can't really see the front bushing but there's no free play at the control arm.

Steering knuckle: again bushing seems intact with no free play.

:iono::iono::iono:

 

[VW-TX]

Cradle might be moving. This will clunk.

Sent from my Nexus 7 using Tapatalk

 

[Gunkata]

passat subframe bolts maybe?

 

[firefly1]

Cradle might be moving. This will clunk.

Sent from my Nexus 7 using Tapatalk

You mean the subframe shifting?

 

[firefly1]

passat subframe bolts maybe?

I do have the subframe spacer kit from ECS. Didn't install them because I don't see any rubbing marks around the subframe. Also my car doesn't come with those well known big/small pesky bolts.

By re-torquing my stock bolts I confirm nothing is loose so I am guessing my stock bolts are doing ok at holding the subframe in place.

 

[SoccerMom]

http://www.golfmk6.com/forums/member.php?u=13877

 

[Merkle]

Damn, you seem to have the basics covered already.

I know this is a rudimentary method, but get the front of the car in the air, have someone kick the tire and see if you can replicate the noise. Bang around on things with a rubber mallet too, that may help you pin point the nose. Check for rocks in the rear suspension, It's happened before.

Suspension noises and electrical issues are just the worst. Good luck!

 

[Gunkata]

Well, when I had DG springs on my GTI, the passat bolts solved the problem.

 

[firefly1]

Damn, you seem to have the basics covered already.

I know this is a rudimentary method, but get the front of the car in the air, have someone kick the tire and see if you can replicate the noise. Bang around on things with a rubber mallet too, that may help you pin point the nose. Check for rocks in the rear suspension, It's happened before.

Suspension noises and electrical issues are just the worst. Good luck!

I'll have to try that over the weekend. Might as well use a pry bar and start cracking all the joints and moving parts see if anything is making the noise.

As for rock in rear suspension arm: will check but doesn't sound like it. It's definitely coming from the front but will take a good look back there regardless.

 

[firefly1]

Well, when I had DG springs on my GTI, the passat bolts solved the problem.

Yea I know that worked for many folks with the DG springs. Correct me if I'm wrong but it seems all the US spec MK6 has the weird looking black stretch bolt in the subframe at the rear most location.

Mine on the other hand came with the "improved" bolts from the factory (VW China with 1.4tsi CAXA). They look similar to the Passat/Audi bolt with full threads and uniform cross section, just slightly shorter.

 

[SoccerMom]

If this problem unique to DG springs on MK6's or does it occur with other springs as well?

 

[firefly1]

Update: I removed the LCA and ball joint today. LCA bushing seems fine but because I already bought new parts so I went ahead to replace them anyway.

When I had the ball joint off the car this is what I found...


There was a tiny crack (maybe about 1/8") on the boot that I couldn't see when it was on the car and the boot looks clean. The grease in the pic is coming out only when I squeeze the boot but the joint itself is still smooth. Replaced the ball joint and put everything back together thinking this is the end of my clunk.

So after 3 hours of work I back the car out and went for a test drive. As soon as I hit the first pothole and the noise is still there. At this point I was furious and about to kick myself. I think I've replace all the wear and tear items at the front end and it gets me nowhere, not to mention two trips to the alignment shop.

 

[firefly1]

Bump...still need help guys... :iono: