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seanmau5
26-02-2017, 10:26 PM
So... Got some bad news the other day. Took my car to Hills Eurohaus to have an engine rattle and DSG knock diagnosed.

Scenario: intermittent engine rattle, only when car is in park or neutral. Doesn't always happen. Occurs under cold and warm conditions. Doesn't worsen with higher revs, actually goes away.

Intermittent DSG knock, only when car is in drive or reverse and idling with my foot on the brake. Doesn't always happen. Goes away with the slightest touch of the throttle or rolling at 'gearbox' speed.

Long story short - timing chain work worth 3k. Potential flywheel work worth 1.6k. Could the 2 issues be related; as in the rattle I hear is also the flywheel (can of marbles issue that I've read about, spring breaks?) and causing the knock as well.

There was also a suggestion of possible worn out mounts allowing the trans to move and knock on another component.

Any input that someone can provide would be awesome thanks!


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Umai Naa!!
26-02-2017, 10:50 PM
Chains and guides, and the dual mass flywheel are both very likely scenarios.

Seen many like this.

Worn engine mounts are a little less common though.

prn31
27-02-2017, 03:07 PM
I had a similar scenario with my R36 at its 105,000 service with both the timing chains and DSG.

I was told my timing chains are rattling. I did a bit of research and checked the noise myself.

Yes, there is a distinct rattle on cold start-up which always disappears after 5-10 seconds. I believe it takes a while for the oil to reach the timing chain top tensioner, hence the rattle.

I also believe that the timing chain guides were improved in later (MY10) 3.6 VR6 engines, but I haven’t been able to find concrete evidence of this. Does anyone know?

I haven’t had any fault codes come up. I know that doing the chains required the removal of the gearbox, making it an expensive exercise - $3k plus.

My DQ250 DSG works fine in normal operation – smooth gear changes, no slipping and no false neutrals. However if I use the paddles, the (down) gearchanges are a bit clunky – as if the revs haven’t been matched properly. I’ve been told that this a clutch pack issue. Again I’ve had no fault codes.

By comparison the DQ250 on our Golf works seamlessly on manual downshifts – obviously it is a lot newer (5 years) and with only 20K on the clock.

I’m hoping that the DSG oil change at 120,000 may improve things. I’m also using the paddles sparingly.

I’ve never heard of an issue with the DMF (dual mass flywheel) in the DQ250. I understand these are supposed to be very durable.

seanmau5
01-03-2017, 12:42 PM
I have very clunky/rough gear changes using the paddles from 1>2 and 2>3 depending on what rpm the car is sitting at when I change gear. No problems going from 3>4 and so on and no problems going the other way.


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tinto
01-03-2017, 04:49 PM
My R36 started to growl a bit when cold.
Does refreshing the chain tensioner bolt delay the whopping bill?

Umai Naa!!
01-03-2017, 06:01 PM
It's a whopping bill either way.

I'm almost certain you need to remove the gearbox to do the tensioner anyway.

May as well do everything else while it's apart.