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General => The garage => Topic started by: Scott D on 30 August 2012, 22:21

Title: High pitch whine noise when revving - MK4 1.8T
Post by: Scott D on 30 August 2012, 22:21

Can hear a high pitched supercharger-like sounding noise that follows engine RPMs and goes quieter when warmed up.

Hear it when revving at idle in neutral, with the clutch engaged in neutral and in any gear while accelerating or coasting below 3000rpm, any higher than that engine and exhaust noise takes over.

All fluids are as they should be, new engine oil less than 2000 miles ago, no boost or vacuum leaks, had belts and tensioners checked and ignoring that noise it's driving very well.

Hard to hear where it is coming from but seems more noticeable from gearbox, downpipe, turbo area under the car rather than within engine bay.

I've recorded videos from under and in the engine bay. It does have a single mass flywheel and always has sounded rough at idle when the clutch is not engaged as in the first vid.

(http://i71.photobucket.com/albums/i150/shoxy84/th_20120830_171605.jpg) (http://s71.photobucket.com/albums/i150/shoxy84/?action=view&current=20120830_171605.mp4)

2nd vid without flywheel chatter
(http://i71.photobucket.com/albums/i150/shoxy84/th_whine-1.jpg) (http://s71.photobucket.com/albums/i150/shoxy84/?action=view&current=whine-1.mp4)

I'm no expert but could a leak in the exhaust manifold, downpipe or turbo cause that noise... loose bolts, gaskets not fully sealed?

Title: Re: High pitch whine noise when revving - MK4 1.8T
Post by: thai-wronghorse on 30 August 2012, 22:25

My mk3 16v sounds just like this at the moment and driving me mad as i can't fathom where the noise is coming from exactly but the exhaust manifold was one of my initial thoughts.

Title: Re: High pitch whine noise when revving - MK4 1.8T
Post by: Scott D on 30 August 2012, 22:42

I'm thinking could well be an exhaust leak, felt a waft of hot air when revving it at idle and a small leak would cause a high pitched whining noise.

Axel stand Sunday  :grin:

Title: Re: High pitch whine noise when revving - MK4 1.8T
Post by: Gambit on 31 August 2012, 11:33

nah sounds more like an overtightened belt

Title: Re: High pitch whine noise when revving - MK4 1.8T
Post by: Scott D on 30 September 2012, 20:27

I had it checked out and the garage thinks it is the differential that is f'ked.

Not sure what to do, can't afford to get it fixed yet and would loose loads selling the car with this problem.

Sorn'ed and a push bike till after winter  :grin:

Title: Re: High pitch whine noise when revving - MK4 1.8T
Post by: Wayne on 12 October 2012, 21:47

Could be an alternator bearing, have you tried the car with the belt off.

Title: Re: High pitch whine noise when revving - MK4 1.8T
Post by: Scott D on 13 October 2012, 15:17

it's looking like could be an issue with the turbo :(

car is at a VW specialist now.