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I have an issue with a 2010 Opel / Vauxhall Insignia 2.0 CDTI Sports Tourer (aka Buick Regal in the States if I'm not mistaken) and I'm having difficulties pinning it down. It's going to be a lengthy read so I appreciate your time.

There is a strange clunky sound coming either from the engine or gearbox whenever I'm decelerating with the clutch engaged (engine breaking) or when I'm stationary with the clutch engaged.

When stationary, the sound doesn't always occur, however, if I repeatedly tap the accelerator pedal, it starts to make a rattling noise. This rattling noise only occurs if the clutch is engaged. Also, when engine breaking, if I disengage the clutch, the noise stops. Also, when pulling away in first gear from a stop, engaging the clutch also produces this noise. After the clutch fully engages, the sound seems to stop.

When accelerating, the sound either doesn't occur or is overpowered by the sound of the engine. I was never able to hear it when accelerating.

I've been having this issue since 2013 and at first it seemed this was only happening when the engine was cold but now it doesn't seem to make a difference.

I've since been to the dealership twice. The first time, they couldn't hear the sound (or probably just ignored my issue altogether), and the second time I took one of the mechanics with me on a drive to demonstrate my issue and at first they thought it was coming from the dual mass flywheel. They took it into the shop and then they said it was coming from the gearbox. They said they can't be sure what the issue is unless they take the gearbox apart. Since the car is second-hand and I'm not fully aware if the warranty still applied, I didn't go through with it since I didn't want to have to wrestle with them to do it under warranty.

I'm also reluctant to take it to the dealership again because, even though they are the least shady mechanics I can find, I once changed my brake pads myself in the driveway and a month later I went to the dealership to replace a torn hose from the intercooler to the intake and they claimed my one month old pads need replacing.

Once I have the time, I'll try and see if I can record the sound and post it here for you guys to hear.

I should also mention that I do not have any difficulty engaging any gear.

Until then, what are your thoughts on this?

EDIT: Here is the sound produced when tapping the accelerator pedal in neutral with the clutch engaged: Engine_Neutral_Noise

Now, this noise is really harsh and loud. The noise being generated while decelerating on the other hand, isn't as loud, it isn't as crunchy and its frequency is constant throughout the engine breaking period. Unfortunately, the mic was not able to pick up the noise while decelerating.

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    Without hearing the sound, I'd guess the throw out bearing. – Ben Apr 9 '16 at 19:47
  • Thanks for the input. I'm doing some work at the moment. I'll try and record the sound in a couple of hours and I'll post back. – user1969903 Apr 10 '16 at 10:39
  • I don't know if notifications are sent out when editing a question so I'm writing this comment to let you know I've uploaded the sound. – user1969903 Apr 10 '16 at 12:02
  • If you use a stethoscope or a screw driver can you narrow down where the sound is coming from? I'm thinking it's either the clutch or flywheel as well. – Ben Apr 10 '16 at 12:29
  • Do you know if this car is equipped with a getrag transmission? – yorTsenoJ Apr 10 '16 at 14:49
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My first guess is also the throw out bearing, but I am not familiar with the newer dual clutch set up. If it is the throw out bearing, I believe they make noise under normal use; that is when the clutch is depressed and in neutral, so no need to worry.

I had this question with a 1995 chevy s-10 pickup with a 4 cylinder. I would always hear the noise and thought the same as you. After 5 years of driving this way, I did have a failure in the clutch plate. On inspection, the clutch plate broke in a very peculiar way. The central shaft assembly has some springs that dampen the drive shaft force onto the clutch plate. The clutch pad itself was still fine. These springs failed and allowed the central shaft in the clutch plate to spin without turning the clutch pads, under high torque conditions. I was able to drive it under low torque, but as soon as I accelerated the central shaft assembly would spin free from the clutch.

This could be your issue, beginning failure of the central clutch plate assembly.

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  • Well, I can't be sure what it is. This winter I noticed that the sound is audible even when the clutch disengaged. When the engine is cold (-20 C over the night), when I first drive it, before it warms up, the sound is noticeable even with the clutch disengaged so I can't be sure it is the clutch plate. Once the engine warms up, the sound isn't noticeable with the clutch disengaged. – user1969903 Jan 27 '17 at 9:54
  • I also heard that, on these models, the oil pump or some o ring along the oil path may fail, oil pressure won't build up to the operating spec and it may cause wear to the piston big end bearing and the crankshaft journals. Once enough material wears off, the piston starts banging on the crankshaft and thus the sound I hear. This is just the opinion of some mechanics I talked to but they haven't heard the car itself. Whether or not this is bogus, it makes want to get it checked out asap. I'll post an update once I get it fixed. – user1969903 Jan 27 '17 at 10:00
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The sound was actually coming from the dual mass flywheel that was practically destroyed. The 2 masses were actually no longer connected as the springs that dampened the 2 masses were completely broken.

Had it changed and now the car is quieter, gear shifts are smoother and the engine vibrations are less noticeable. The engine also seems to be a bit less responsive when reving in neutral.

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