To start off : if you want something refunded or replaced, it has to be faulty or broken. A lot of turbochargers whine, some more than others. So I very much doubt you'll be able to get your money back, or a replacement, on that basis.

Now, a bit more detail. When a turbo (especially on a diesel engine) fails, its quite often due to oil having carbonised in the bearings / feed pipes. Basically, the high heat of the turbo burns oil, leaving a solid mass that clogs up the pipes and bearings. Things stop getting lubricated, and the turbo fails.

When you had your turbo replaced, did you get all the pipework replaced too ? If not, then it is possible that the turbo still isnt getting enough oil feed, and it could well be going the same way as the first one. (imagine the turbo is a heart, you've had a heart transplant, but all the furred up arteries due to poor living are still there, and it's ready to have another heart attack due to that)

If you provided the turbo to the garage (I notice you only say their price was to fit it, not supply and fit), then they may have just done what you asked for. After all, you provided the turbo, if you wanted all the pipes replacing, then you would have provided those too.

The devil is, as usual, in the details.

Is everyhing else OK. If turbo pipe work is leaking or if the exhaust is blowing you may hear an increased whine. I had this with a VW Passat a few years ago which proved to be a failing exhaust downpipe

Edited by Big John on 15/11/2014 at 23:21