Rear Top Mount Knocking

[MikeBee]

Hi All,

I've got a knocking from the rear of my Edition 30. Initially I thought it was the hatch not closing properly but I've adjusted the stops for the hatch and it's now nice and solid. Trim is all solid, so I started checking suspension bits. Droplinks all ok, bushes look fine. The one bit that looks super dodgy is that I can wiggle the top of the damper strut on each side and there is a load of play.

It looks pretty easy to replace the rear top mounts, but do I need a new top mount and a new bump stop or do I just get a new bump stop and replace the old one? And are there any uprated parts that I should consider (TT-S, S3 etc)?

Thanks!

[pudding]

Rear top mounts rarely go on these cars.  Is the play between the damper rod and damper body, or between the damper rod and the top mount?   New mounts for the rear are quite expensive, I think around £50 each when I did mine, and yeah, they are easy to fit.  Just be careful you don't cross thread the 2 bolts as they are at an angle.

[AJP]

Interested in this. Like we discussed, Pudding, I recently got a tiny knock at the rear after fitting a new set of coilovers.

I went through the usual checks - something loose in the spare wheel well, adjusted the boot rubbers etc - and it's still there.

I initially thought that the firmer spring and damper of the coilovers was causing something loose to make enough noise to notice, and that the softer previous setup didn't highlight it. But now I'm not so sure.

I didn't replace the rear top mounts like I did the fronts as I assumed the same as what Pudding is saying - there doesn't seem to be much to go wrong.

I need to get under for a proper look really!

[MikeBee]

Cool thanks for the reply. I hadn't considered the damper rod and the damper body itself, but it's possible. I only grabbed the damper body and wiggled it.

I will double check.

[pudding]

I did my rear top mounts a couple of months ago when I threw all the VWR stuff on.   At 110K miles, the rear top mounts showed zero wear!

Did you chop down the rear bumpstops the same amount as you lowered the car by, or did you leave them factory length?

Did you check the rear drop links and ARB bushes etc?  Uprated suspension puts extra strain on some of the components.

These cars are just noisy over bumps anyway.  The rear top mounts are TINY and 90% metal! The front mounts are somewhat lacking in the rubber department compared to the previous generation as well, but it's partly why the MK5 platform handles well. Less squidge.  I get a slight knock from the back only on cobbled streets and block paved roads, but I just put it down to the nature of the beast! It could just be damper noise.  The VWR dampers are noisier than the OEM ones, but it's not really that noticeable unless you listen hard for it.

[pudding]

Cool thanks for the reply. I hadn't considered the damper rod and the damper body itself, but it's possible. I only grabbed the damper body and wiggled it.

I will double check.

Yeah my gut instinct was damper knock.....which is the damper itself rather than any of it's mounting hardware.

[AJP]

@Pudding If I remember correctly from having a nosey in the box before I had them fitted, the Vogtland rear dampers come with their own bumpstops and dustshields. So just pull out all the old and replace with new. No trimming needed, in theory.

Incidentally, the knock is just how you describe it over cobbled streets etc, at low speed. I'm inclined not to worry too much as it all works rather well for a budget kit - with no funny noises - once up past 20mph or so.

[pudding]

Sounds normal to me mate.  And you've just reminded me actually..... I was in the back of a brand new Tiguan over the weekend, and guess what.....knocking from the back over bumps!  Those things have a surprisingly stiff/harsh ride for a soft roader.

I think it's just damper noise and because top mounts are so small/stiff on German cars, it comes through to the cabin as a knock.

[AJP]

Yeah it's not keeping me awake!

What might though, is a new 'mystery creak' that I just can't work out. It happens when pulling out of or into a parking spot - so could be caused by any number of things like steering, clutch etc.

It's gone before I get the chance to pinpoint where it's coming from, but it sounds close, almost like it's coming from the interior. But I have a feeling it's just being efficiently transmitted into the cabin. Possibly front top mounts, but it's too 'shrill' a noise, and also they're only a few months old. Rack? Hmmm. Hope not.

It's hard to describe in terms of how it sounds.

It's hard to pinpoint in terms of location.

It's hard to replicate.

God damn.

[AJP]

Sorry to hijack your thread by the way @MikeBee!

[MikeBee]

Sorry to hijack your thread by the way @MikeBee!

Haha no worries!

[pudding]

Lol, maybe we need a super thread entitled "Strange noises and possible causes" 

@AJP that's a weird one for sure.  Only does it during steering, and I'm guessing quite a lot of lock angle?

[AJP]

Lol, maybe we need a super thread entitled "Strange noises and possible causes" 

@AJP that's a weird one for sure.  Only does it during steering, and I'm guessing quite a lot of lock angle?

I couldn't tell you for sure whether it's steering (and how much), or drivetrain, or something else. But it happens as I'm setting off from stationary.

I'll keep an ear out for it today and report back if I suss it!

[MikeBee]

So disappointingly I had my MOT today and asked the tester to check out the dampers and top mounts at the rear. Nothing wrong...

Back to the drawing board 

[pudding]

I think MOT tests only fail the dampers if they are leaking.  Any oil spotting on yours?

Time to get it on the ramp and give everything a good hard whack.  Some worn parts that aren't physically loose to the touch can sometimes reveal themselves if you hit the tyre hard with a hammer, which simulates the behavior of driving over bumps.