Hi, 

First off I drove to work this afternoon with no issues at all. Left tonight and thought it felt funny, when on the main road I accelerated and noticed i had no boost at all although the engine seemed to be fine otherwise. On the motorway I sat at 55-60 (50 speed limit) when the limit went to 70 I put my foot down in 5th gear still no boost. As soon as I hit 70 the engine warning light came on a solid red but didn't seem to change the way it drove and slowly hit 80 mph, sat at that for fine for around 10 miles. It was revving fine so don't think it went into limp mode. Don't think there is any smoke out the back but it was dark. Car has done 85k and has been running fine since I bought it at beginning of February. Really hope someone on here can tell me it ain't the turbo or something else expensive. Switched off ignition and started straight away when I got home and light was off. Can't really find much else on these forums that sound the same. 

Thanks all. 

So I had a mechanic take a look and turns out the turbo is passing oil. I have managed to source a reconditioned one for £300. How difficult is it to change? I am not a mechanic but do small jobs on my own motors (brakes/oil changes etc). With a bit of instruction is this something I could attempt myself or am I better letting a professional do it? How long does it take to change on the 1.8 tdci engines? 

I cant help with how hard a job it is but you will also need to clean out the pipe work and intercooler.

It's not hard to do but access is difficult with the turbo being behind the engine on these.  You'll have to spend a lot of time on your back, much easier and quicker on a ramp but ultimately depends how much the labour quote will be.  You may also find you get no warranty from the garage when supplying the part yourself so it's worth checking that.

Been on holiday so getting chance to reply. Thanks for info guys. New turbo has been fitted but now having a couple of new issues that have been present since I got the car back and the guy that fitted the turbo isn't sure what it is. I now have boost and car runs great but:

1. Engine systems fault light is on when starting from cold but disappears after 2 mins. Orange engine light is on constant. (all faults were cleared after fitting turbo) 

2. Goes into limp mode if I go above 70 mph. 

3. If air con is ON engine systems light comes on again but goes off if I turn air con off?!? 

Guy hooked up code reader today and came up with MAF sensor and overboost issues. Changed Maf and air filter then cleared codes. All lights are now off but goes limp as soon as I hit 80. Flick engine off for half a second then on and boost comes back until I hit 80 again. Hooked reader up again and throwing up MAF issue everytime after it's been cleared. 

Anyone have any ideas as to anything that could be causing this? 

Thanks

Air con issue, really weird one. No problem before New turbo. 

https://youtu.be/lmGmWEH0LA0

No idea if it would be similar, but my old Mondeo tdci used to do something similar with the engine warning light. With the engineer light off; Find a hill and drive up it with the engine in a higher gear than you'd usually use (so you have to have the pedal to the floor & the engine is having to work) and see if that provokes it. If so, for me, it was the injectors to blame, which I believe might have been affected by your turbo passing oil into the engine.

Like I say, I don't know, just an educated guess based on my own experience.