Help me solve this technical mystery - PLEASE

[W55LSY]

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

 

[nluk100]

Definitely gearbox related IMO. Probably a bearing in the gearbox.

Have you checked the oil level? Maybe a cheaper first solution would be to replace the oil and see if that helps?

 

[W55LSY]

Definitely gearbox related IMO. Probably a bearing in the gearbox.

Have you checked the oil level? Maybe a cheaper first solution would be to replace the oil and see if that helps?

I did think about oil transmission oil after posting. I'll be doing that tomorrow.

Yeah the likelihood of gearbox issue makes sense and is of particular concern. It's a £400-£600 job just to get the thing out.....

 

[nluk100]

I did think about oil transmission oil after posting. I'll be doing that tomorrow.

Yeah the likelihood of gearbox issue makes sense and is of particular concern. It's a £400-£600 job just to get the thing out.....

Who's charging you that much? A decent VAG specialist can have the gearbox out in a couple of hours, and there are 100's of used gearboxes out there for your engine, and are around £150.

 

[Sayam]

2/3 labour to remove the box should cost no more than £150. That's where I'd start, and looking at the mileage, I'd replace dual mass flywheel and clutch kit when rebuilding as it'll save you the labour in the future - assuming you'll be keeping the car.

 

[W55LSY]

Who's charging you that much? A decent VAG specialist can have the gearbox out in a couple of hours, and there are 100's of used gearboxes out there for your engine, and are around £150.

Really? Ok I’ve got that wrong then. I haven’t been quoted that much, it’s just the sort of numbers I’ve seen banded about on here.

that’s good to know Though, as it’s getting worse, I think?!

 

[W55LSY]

2/3 labour to remove the box should cost no more than £150. That's where I'd start, and looking at the mileage, I'd replace dual mass flywheel and clutch kit when rebuilding as it'll save you the labour in the future - assuming you'll be keeping the car.

Yep makes sense. I intend to keep the car forever. I really need to stop hoping it’s going to magically disappear and get someone to look at it before it escalates

 

[Sayam]

Yep makes sense. I intend to keep the car forever. I really need to stop hoping it’s going to magically disappear and get someone to look at it before it escalates

I've done the same thing with my car. It's easy to put off - don't wanna be without a car, the headache inconvenience etc etc it's easy done...but get it checked sooner rather than later as bills tend to go up not down lol.

 

[aqibi2000]

Aside from the gearbox why can’t it be the front diff?

you can buy £20 additives and see if the noise changes if it does you know where the culprit is


“Fully maintained” can bet you it’s not had a diff oil change let alone the gearbox. You’re at 110k miles

 

[W55LSY]

Aside from the gearbox why can’t it be the front diff?

you can buy £20 additives and see if the noise changes if it does you know where the culprit is


“Fully maintained” can bet you it’s not had a diff oil change let alone the gearbox. You’re at 110k miles

Hadn’t thought of that. I’ve never had a diff issue so wouldn’t know it sounds like.

thanks for the advice. I’ll add it to the list of possibilities

 

[mister.c.]

Got to the bottom of it yet?

 

[W55LSY]

Dual mass. New clutch kit going in, when I can afford it!