I have a 2002 octavia 1.9 tdi. Over the last year or so the turbo would occasionally cut out under acceleration,only for it to come back on after turning the ignition off. Diagnostics picked up this familiar problem but not got round to changing the pressure switch. Over Christmas it has now developed quite a loud whistling noise under acceleration as the turbo seems to spool up. Cant really hear it unless the engine is under load. I am hoping that it is just a pipe somewhere as i am selling the car soon and dont want to be forking out money on repairs. Any advice would be great.

Usually pipework just pops off under heavy boost without warning, it may well be the turbo on its last legs. Limp mode was most likely caused by overboosting, is the car mapped?

Thanks ben90, not sure about the remap as i had it second hand. It does seem to go very well considering its only the 90hp version though. The limp mode is something like a boost pressure switch. Bloody hope it isnt the turbo thats all

I had whistlling under hard acceleration on a previous (not VAG) car when the turbo bearings started to fail. Eventually it sounded like a police siren when I put my foot down. Does your whistle increase in note as the revs rise?

Overboost leading to limp home mode is caused by carbon build up on the variable angle vanes In the turbo being held by the crud build-up. I had my cleaned professionally by a specialist under warranty, but search on here for Mr Muscle for a DIY solution. If the bearings are gone then it's a "new" turbo from a scrappy.

It does sound like a police siren,and yes it increases as revs rise.  Not sounding to promising now then.

SOLD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Hard to believ how much interset i got in the car, and not one person picked up on the turbo noise. Back driving my 07 VRS again now. Think im in love again