Trying Eliminate Mysterious ‘whine’ - HELP!!!

W55LSY

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I need ideas guys and girls. I’ll put this as succinctly as I can.....

(2010 A3 2.0 tdi 170 CR 110k)

CAR HAS BEEN WELL MAINTAINED - FULLY DOCUMENTED FROM NEW.

- I have what is best described audibly as a ‘whistle/whine’

- started 2/3 weeks ago

- no slow build up that I noticed.

- One day it just started ‘whining’ - instant

- ‘whine’ is consistently older with increase and whiter with decrease in speed AND load.

- it could have been loose trim/mirrors etc. IT’S NOT

- Whine DISAPPEARS completely when clutch is FULLY engaged, Regardless of up or down shift or load.

- whine is present even when coasting (in gear)

- gear change and selection seem fine

- Driveability seems unaffected, (I think)

- Has it got worse/louder during these 2/3 weeks? ‘Maybe’ it has become more audible. If so, it’s minimally perceptible.

My IMMEDIATE reaction was it sounds like a boost / turbo issue (classic whistle/whine). HOWEVER, it’s dictated by clutch IN/OUT.

With NO mechanical input, my ideas so far :

- aero issues - NEGATIVE
- turbo (general) - Logically it’s a no
- boost sensor etc - logically it a no
- fuel / airflow /rads etc - logically its a no (as per boost)
- top/ bottom end - 99.9% negative

Rationale for above is that ‘Whine’ disappears upon full engagement of clutch. No overheating re lack of coolant/air or oil.

SO.....TRANSMISSION:

- thrust bearing - unlikely as only FULL clutch engagement Stops the whine
- dual mass - unsure??? Past experience (BMWs) dual mass is basically entire clutch with slippage symptoms etc ??
- full clutch - No slippage under load and engagement is smooth
- gearbox - tight with no change in selection
- synchro - no selection issues

I really need some help on this. I’m fairly handy but I have no workshop/lift/proper tools etc

More than happy to pay an indy for repair etc, but not hours of labour on diagnosis. I just can’t afford it.

any ideas on this common VAG CR engine are more than welcome. Even better would be Experience of what I’m describing.

Cheers guys and girls
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Reactions: beno70
I seem to have a similar whine that's only just become apparent I'd say, after a recent 4500 km road trip. - B8.5 S4 S-tronic with 110k kms.
- Actually I guess this is a completely different transmission though...