406 HDI 5th Gear Noise

[Malc]

Just bought a 2001 406 Hdi which has a high pitched whine after selecting 5th gear.
It varies in intensity with accelerator pressure from hardly noticeable to slightly annoying.
I'm not exactly sure if it is coming from the gearbox or elsewhere.
Anyone any ideas.

[steve_earwig]

Hello.

That's not the turbo you're hearing is it? Is it a constant whine that changes pitch with road speed or with how hard you're pushing the loud pedal? I can't say I've ever heard a gearbox that's noisy in just one gear, it's usually all of them.

[Malc]

Thanks your reply Stuart.
Yes! I had my own suspicions re turbo but if you're previous car for the last ten years was a petrol-engined 1983 Opel Ascona sans clinks clonks or other weird pulley/turbo noises and nary a single mechanical problem, I thought I'd seek out advice.
Is this irritating whine normal?

[DaiRees]

Stuart.

Stuart Earwig

Welcome to the club Malc

Where are you? Put you location in your profile . Maybe you could meet up with another HDi owner to compare noises?

[Malc]

I'm in France Dai and the last thing on my mind would be to compare 406 noises with other Pugs from this ilk!
Mind you if it meant turning back the clock for one more pint in Ye Olde Red Lion Inn Tredegar, I could be tempted!

[DaiRees]

So are you from these parts originally then?

[Malc]

Scottish by birth, Dai... Had friends in Pen-y-Graig and the Rhymney Valley too many moons ago. Happy days!
Back to the Pug and possible turbo whine and any further welcome comments and/or theories.

[steve_earwig]

I've been having a squint on the parts diagrams, I thought these gearboxes were well past being a 4-speed with a 5th grafted on but apparently not. The diagram shows an extra gear wheel in there for 5th but it doesn't show which shaft it lurks on (reverse? ). SO I guess it's possible to get noise from 5th without noise from any other gear. If it is coming from the 'box I guess you could try changing the oil (1.9 litres 75w80), perhaps slapping in some Molyslip or similar (look for the magic words "molybdenum disulphide") and see how it goes. If this doesn't clear it, I guess you need to either find someone to rebuild it (leave the 'box in so they can have a listen, donate a kidney), replace it or buy a louder stereo