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Discussion Starter #1
Hi all,

Driving along in my GT with the windows down enjoying a rare spell of nice weather in the North East...no music on (which is even more rare), and noticed a 'wobbly' sound.

Started to experiment to see how it came and went, and it seems the sound is present at around 2,000rpm or more. It doesn't matter which gear, and car speed makes no difference. Dip the clutch and the sound disappears instantly, since the revs drop off.

It's quite difficult to hear if the sound disappears the higher the RPM goes due to the hybrid turbo sound masking it. From what I can hear, it doesn't disappear.

From this I'd say it can't be any of the final drive components, wheel bearings, driveshafts etc., and also could suggest it is directly related to the clutch/flywheel, since dipping the clutch makes the sound disappear.

The other side of the clutch/flywheel I'm unsure about...I'm thinking that if it was anything between the engine and the flywheel, dipping the clutch would make no difference since all the rotating parts are still rotating, albeit starting to slow down?

If so, I know the clutch is well on it's way out, a lot of slip especially in the higher gears where there is a lot of torque, so would a failing clutch/flywheel be consistent with this 'wobble' sound?

I'm already taking her to Dan (Pud) at Autolusso Penrith next weekend where amongst other things the clutch and flywheel are being changed for the SMF and GTA clutch.

Any thoughts on this 'wobble' sound in the meantime would be much appreciated
 

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well obviously clutch related as it disappears when you depress the clutch pedal, you are correct that both clutch and fly will still rotating but what is key here is that they wont be in contact,maybe you have some DMF issue that is only transmitted through the drive train when the clutch plate is in contact with it..?

Dan will check it all when he has it apart so I am sure you will get a resolution either by changing the clutch and fly or by the issue causing your ''wobble'' being obvious when its all apart.

I have just had this conversion done and must say its the Boll***s! a good choice if you have the hybrid..

keep us posted and good luck, I don't anticipate any problems for you as you are in excellent hands with Dan...:thumbup:
 

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Discussion Starter #3
well obviously clutch related as it disappears when you depress the clutch pedal, you are correct that both clutch and fly will still rotating but what is key here is that they wont be in contact,maybe you have some DMF issue that is only transmitted through the drive train when the clutch plate is in contact with it..?

Dan will check it all when he has it apart so I am sure you will get a resolution either by changing the clutch and fly or by the issue causing your ''wobble'' being obvious when its all apart.

I have just had this conversion done and must say its the Boll***s! a good choice if you have the hybrid..

keep us posted and good luck, I don't anticipate any problems for you as you are in excellent hands with Dan...:thumbup:
Thanks for that :thumbup: I just wanted to make sure I wasn't missing something obvious with my deduction that it was clutch/flywheel related

Definitely in good hands with Dan, been over there a few times now, I was just concerned it could be something more sinister which may require more immediate attention :)
 

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Discussion Starter #5
I tried something I hadn't previously tried on the way home tonight. Dipping the clutch but holding the revs up...the wobbly sound stays when doing this.

So to me this could then be anything that rotates between the flywheel back to the engine. I hope it is the DMF since it's getting removed soon :paranoid:
 

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Discussion Starter #7 (Edited)
Drive shafts or inner cv joint are likely candidate but usually you will feel accompanying vibration.
With the sound disappearing when depressing the clutch I don't think it can be on the driveshaft side of the clutch though. I'm hoping it is the DMF

Edit: The wobble is still there when stationary and out of gear...so it can't be the DMF :( I dread to say it, but turbo??
 

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Drive shafts or inner cv joint are likely candidate but usually you will feel accompanying vibration.
Ive got the above, doesnt go with the clutch in as the joints are still turning. Fingers crossed its all clutch related as you are swapping it all out soon anyway! :)
 

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Can you hear the sound with the car stationary or is it speed related?

If you can hear with the car not moving i'd be tempted to remove the aux belt and then have a listen. Lots of components can make all sorts of misleading sounds.
 

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Discussion Starter #10
Can you hear the sound with the car stationary or is it speed related?

If you can hear with the car not moving i'd be tempted to remove the aux belt and then have a listen. Lots of components can make all sorts of misleading sounds.
It's not speed related, can hear it when stationary and out of gear so it's definitely not the DMF.

The rpm coincides with the turbo spooling up which makes me paranoid straight away…turbos haven’t been my friend in the past!

I’d try removing the aux belt but wouldn’t have a clue where to start. If it was the aux belt would this not be audible even below 2,000rpm?
 

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What does the noise sound like? Wobble is a bit difficult. Does it squeal, tick, thud, clunk, whistle. Could it be a boost leak? Is their performance loss or smoke? Check the powersteering level. Maybe tip some water on the aux belt and see if quietens anything.
 

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Discussion Starter #12
It's so hard to describe, I'd liken it to a wheel bearing type 'wobble'. Not metal on metal, or a squeak, or a tick, thud, clunk or whistle.

I do believe I have some sort of boost/turbo issue which has been going on for a while now, whether it's related or not is anyone's guess.

On a more positive note, I'm now heading over to see Dan and leave the GT with him for a week or two. Plenty other work to do but hopefully a nice easy fix to this problem :thumbup:

Feel happier now I don't have to drive around another week with it.

Thanks for the help anyway, will report back as to what the issue was when we find out :)
 
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