Rubber / hinge noise when driving over humps / roundabout

[defever]

Hello forum users,

I've been having hard time trying to pin point what is causing this "rubbery" / "old hinge" noise when driving over humps, roundabout, turning, slowing down.
There's no pattern as to turning left or right, but more prominent when at slow speed over non-smooth surface. It's definitely associated with heat: the noise is more audible after the engine is warmed up or in a warmer weather (t-shirt weather).

It just sounds like driving an old truck / van with poor suspension or being in a retro bus with poor seat spring!

Here are some attempts to record the rubbery / old hinge noise (please ignore the constant cracking noise, just my phone hitting the vent due to vibration), which is quite prominent:





In attempt to pin point the component that's causing the noise, the following were replaced since the noise started (approximately last 10,000miles):

• both tie rod ends (though they can be moved by hand, not loose)
• both tie rod rubber gaiters
• all upper and lower control arms both sides (OCAP)
• transmission mounts
• engine mounts

I think the following are still suspects, but not yet investigated (they are beyond my DIY ability):

• both suspension struts
• subframe bushings
• CV joints
• Anti-roll bar bushings (I can do this, but they looked perfect when I replaced the lower control arms)

Replacing with OCAP control arms instead of Lemforder was probably not the wisest choice but should a brand new OCAP arms cause this noise? The old arms were making the same noise but were either "TWR" or had "Audi Ring" logo on them. Most of the old arms had bushings cracked or torn, but the noise is still consistent after replacing all control arms. That lead me to think maybe the noise didn't come from the control arms after all.

What do you think the cause of the noise is? I don't think it's an imminent issue but just something rubbing somewhere?

Any suggestions or directions will be very helpful, as always.

Happy driving.

[fourringsrus]

Some arm bushes ( b4 for example ), will not seat correctly if when fitted, the weight of the car is not on the suspension,thus leading to short lifespan.
Something says to me that unless your road surfaces are the worst around, your car seems to crash and bang over the bumps, so maybe a closer look at the shocker inserts would be prudent.
Have you looked at your rubber exhaust hangers
Might be a steel/metalic squeek rather than rubber, all these parts will alter in behaviour due to changing temperatures
Try to get a large pal to bounce the stationary car whilst you inspect the car , quite vigorously, up and down and even apply some sideways motion at the same time as bouncing
Good luck

Stuart

[rowdy-999]

I would say subframe mounts. Get it on a ramp for a closer inspection.

[defever]

Thanks very much both for your comments!

Some arm bushes ( b4 for example ), will not seat correctly if when fitted, the weight of the car is not on the suspension,thus leading to short lifespan.

When I replaced the lower arms, I lifted the bearing housing with a jack so that the suspension and arms are "loaded" and torqued the bolts as specified. Unless the OCAP arms are so poorly made, the arm bushings should be sitting as they are meant to.

Something says to me that unless your road surfaces are the worst around, your car seems to crash and bang over the bumps, so maybe a closer look at the shocker inserts would be prudent.

When you mean shocker inserts, do you mean the suspension strut insert at the body on top and the bolts on the lower front arm at the bottom?

Have you looked at your rubber exhaust hangers

No, and probably best to replace them as they are cheap and I doubt they've been replaced since factory. Thank you for the suggestion.

Might be a steel/metalic squeek rather than rubber, all these parts will alter in behaviour due to changing temperatures

I hear two distinct noises; one rubbery friction type and another "old hinge" type noise. The hinge type noise is more audible when going over humps (i.e. vertical movement of the car) and rubber noise is more prominent with turning (i.e. horizontal movements). I completely agree with you and this is what's making me wonder if it's something associated with a subframe bushings?

Try to get a large pal to bounce the stationary car whilst you inspect the car , quite vigorously, up and down and even apply some sideways motion at the same time as bouncing

I tried this myself, but I couldn't produce any noise; I'm either not heavy enough or not in the right place to hear the noise.

I would say subframe mounts. Get it on a ramp for a closer inspection.

This is what I'm starting to suspect it. There's no mention on the full history of the car (or at least what I was given when I bought it) of any work done on the subframe since factory, and the fact that the control arms and transmission/engine mounts needed replacing in the last month or so is making me wonder if the subframe bushings are also in need of replacement. I'm not confident enough to touch the subframe by going under the car using axle stands so I will ask a VW specialist garage to have a look. Plus I have an ongoing small oil leak from the sump pan gasket so hopefully I can ask them to have a look at both of them.

Thanks very much once again for your thoughts!

[defever]

Little update on this...

I had a look at under the car just now and this is what I found (my gearbox is EEN model):

• 2x front subframe bushings: the two front ones (8D0399415E) by the alignment holes and under the engine mounts had more play than the control arm bushings when I applied leverage with a crow bar. They need replacing, I assume.
• The rear bushings on the front subframe bushings (8D0399419N) by the transmission mounts didn't budge even with the crow bar. The metal plate underneath them (8D0399541B / 2B), often used as jacking / axle points were securing the bushing so I couldn't tell very much.
• The exhaust rubber hanger (8D0253144R): The one by the centre silencer was very stretched (though not torn) so I might as well replace the two rubber hangers.
• Rear axle beam bushings (8D0501541A): They had cracks on the rubber I can see and had lots of creaky movement with crow bar! So they need replacing too.

The control arms, anti-roll bar, engine and transmission mounts were replaced by me so I double-checked that they were secure.

When I rocked the car holding on to the roof rail, the creaking noise seemed to come from the rear axle rather than the front, which I previously haven't realised. When jumping on the front bumper or the fender, there's hardly any creaks or added noise. And when I go around to the rear and rock the car, it creaks like an old truck.

So I'm now thinking it's time for all the subrframe and rear beam bushings to be replaced...I cannot DIY on these tasks as I don't have engine support beam or don't want to gamble on taking the frames apart and getting stuck on removing / installing the bushings.

QUESTION: How many hours will it take for a VAG specialist independent garage to replace all subframe & rear beam bushings and do the alignment??
4-5hrs of labour? While the subframe is down, I may ask to have a look at the oil sump gasket and replace if necessary which has been seeping oil for couple of years now.

Depending on the estimated cost of getting this done at a garage, I may have to consider, for the very first time, if it's worth keeping the car...(which is a sad sad feeling)

Thanks very much and happy motoring!