Knocking / Clunking Under Power

[SkyQuake 70 1 Cars]

Dear All,

 

I'd appreciate your help with the following issue! Having passed it's MOT last year, the GTI has been out on a couple of excursions, and hasn't broken down, caught fire, exploded or instantaneously disassembled itself, so far at least!

 

I have however been noticing some worrying noises from the engine bay. The noise is a pronounced clunk (something hitting the shell), and it seems to come from area of the front RH suspension. It started off quiet and occasional, but seems to be getting worse and worse.

 

It occurs when I put the vehicle under power (and remove it), but only if throttle changes are above gentle. If I drive gently, it does not occur. It almost sounds like something is sliding backwards and hitting the shell when the power is applied, and it slides forwards again when the power is removed. I cannot reproduce it under sharp braking, and it is more difficult to get it in first gear than second/third.

 

I cannot detect any movement in the suspension, even when rocking the wheel back and forwards / side to side vigorously. I've had the wheels off, and double checked all suspension & subframe bolts for tightness. I originally suspected the ARB, but could find nothing wrong at all. As far as I can tell, there is nothing loose or floating.

 

With the wheels chocked, and the girlfriend rocking the car in reverse, I can get it to clunk, but I cannot see anything tapping. As far as I can tell, nothing is close enough.

 

Suspension bushes are all brand new, as are the ARB bushes, drop links, shock struts, and top bearings. I have also changed the engine mounts for new ones, and this has no effect.

 

What else is there that I haven't checked? Any other ideas of how I could find the culprit?

 

Any advise is greatly appreciated.

 

Many thanks,

 

Mike

[oak tree garage 1 1 Cars]

hi mike have you checked /changed the lower engine mount that has the bolt through the subframe

 

ian

[benny205mi16 19 1 Cars]

I had this on my car, I changed all the engine mounts and it was cured. So as above check these.

[farmer 328 1 Cars]

If you change the mounts use genuine as the pattern one's are guff.

[SkyQuake 70 1 Cars]

Dear All,

 

Many thanks for your responses above. I did change all of the engine mounts, for Lemforder ones, which I had expected to be fit for purpose. I guess I'll look into getting some genuine ones and do the whole job again!

 

Farmer - What do you do with the Lower RH engine mount? Main dealer says it only comes with the casting (which is astronomic, and would involve me draining my gearbox and removing drive shafts, so no thanks!). Can you get just the bush anywhere, or is there a decent aftermarket one I can get hold of?

 

Many thanks again for your help.

 

Mike

[farmer 328 1 Cars]

Mike

 

There is a genuine bush available on it's own.

 

I do have the complete casting and bush (new) that I would sell, but I would want £100 posted and in my opinion just take you old unit off and push a new one in.

 

I would go for a baker bush in the lower mount and genuine elsewhere.

 

Been told the above set up is the best for road use.

[welshpug 1,666]

for the lower mount main bush, order the one listed for the diesel 205, its the same bush but one of the oddities of servicebox its not listed for the XU engine on its own, the parts guy really should have known the diesel one would fit.

 

 

 

1809 16

ENGINE FLEXIBLE-BUSH

 

however, if you have a correctly fitted Lemforder bush I would leave it till it wears out, with a standard engine and exhaust they will be fine and highly unlikely to be the cause of any clunking.

 

do you have a standard exhaust?

[SkyQuake 70 1 Cars]

Hi Chaps,

 

Many thanks for that. I think I'll go with the baker one, as I'm sure it's the engine rock which is causing the clunk.

 

The exhaust is standard all the way down to the back box, which is a stainless Magnex. I have checked this very carefully, and re-adjusted it several times, and I'm sure it's not the cause. Whatever it is, it's definitely drivers side of the engine...

 

Cheers again,

 

Mike

[welshpug 1,666]

Ah, check the upper mountingbush is tight enough, there is a special tool but not many have one so resort to a punch, often never get quite tight enough.

 

Can cause a clunk like the one you describe.

[dcc 855]

checked the top mount of the strut is tight? what about your subframe mounts.

[SkyQuake 70 1 Cars]

Ah, check the upper mountingbush is tight enough, there is a special tool but not many have one so resort to a punch, often never get quite tight enough.

 

Can cause a clunk like the one you describe.

 

Ah yes. I do remember scratching my head for a while, wondering how to put a drive across the crennelations! If I remember rightly, I tapped it round using a screwdriver, so it might not be properly tight. I'll check that one and see if it's the culprit! Cheers.

 

checked the top mount of the strut is tight? what about your subframe mounts.

 

Thanks DCC. The top mount of the strut is definitely tight, I've checked and double checked that one, and there's also no visible markings of it moving. The subframe is also good and tight.

Edited January 20, 2014 by SkyQuake