High pitched whistle - turbo?- or something much worse?

Hi all

Seems when I fix one problem another appears!

Had my driveshaft done at last then about a week ago I noticed a pronounced low pitch whistling which gradually increased in pitch as I accelerated. Never noticed it before beyond the normal whistle from the turbo when it kicked in. Now it's louder, only happens on acceleration and gets to a high pitch whistle (or is it a whine?)

Had a look around the forums re turbo/manifold and I find it hard to differentiate between this and a 'whine'.

What I know so far.

* Car serviced over a month ago with proper oil
* Car does not show any smoke
* Acceleration is the same
* no warning lights
* No cabin smell
* No engine work done recently
* Doesn't whistle or whine when holding a steady speed
* MPG no different

Stuck my noggin under the bonnet and the noise may be coming from he back of the engine but not sure. Checked for fumes but I couldn't say for certain in case manifold had gone.

Was just about to sell the car this week but don't want a buyer landed with a repair bill! (Honest seller-who knew!) . Car is 04 Tourer CTDI with 198k but the engine has done about 130k- previous owner replaced it.

So I'm stumped- any ideas guys as I have practically no symptoms connected to a manifold crack or smoking due to turbo damage!!

Sounds normal from the description

Yah, sound normal to me as when you put foot down to increase speed, once connected to turbo, the whine sounds begin, but mine is only little I can hear. It's normal for this car I think.

its weird that its just suddenly become more pronounced - this morning when I drove it at lower speed/revs it is really loud and low pitched (like a siren at the low tone) and sounds like wind coming through the dashboard!! best described as when you try and whistle while sucking air between your lips!! but beyond any symptoms.......... hope the new buyer isn't put off!!

Check your airbox and intake pipework. Its possible the mechanic may have dislodged something when doing the driveshaft

Also check that the gearbox was topped up with mtf after the driveshaft was fitted.

Yes good point lets hope it's not gearbox whine!

hi guys- yes the gearbox was drained and refilled although the noise happens when revving the car stationary as well as on the move- ill check the oil level as well.

will check all the airbox pipework tonight as spookily it only started making the noise after the shaft was fitted !!

cheers

Well folks I am still stumped.....

Checked all the airbox pipework, taken it apart and put it together again- tightened all the jubilee clips- been round the back of the engine checking the pipes to and from the turbo- no obvious splits and cant feel any air blowing out of them
Gearbox oil at the correct level

Bizarrely the whistle noise seems worse at 1500-2000 rpm then gets higher pitched like the turbo should. almost sounds like a police siren from a distance (wail!) but really pronounced in the cabin. Still no symptoms either

Gonna have to give up the ghost and get it looked at ....watch this space - thanks for all the advice too - Im dreading that its actually the turbo on its way out

Mate, it sounds like turbo to me... Get a recondition one from eBay mate.

managed to record it!!

http://youtu.be/FwBvlqFAuPc

I have a whiney alternator and it's much higher pitched than that. However i have a petrol and it seems to occur in a similar fashion. My wife also describes it as like a distant police siren.

Does it become more pronounced when the A/C is on (alternator under higher load)?

That does sound turbo related to me. Maybe turbo has had it?