oil by filler cap and no whistle from the turbo

[villatone]

hi all
i have a 55 plate bora TDI 130 HIGHLINE only done 49000 mile just noticed that i can't hear the turbo whistle like i used to when accelerating,on looking under the bonnet,around the oil filler there is a rubber collar there was some oil in there,i cleaned it out went for a bit of a burn when i got back home there was a bit more oil in the collar.
would anyone know if i have a problem and also could this be related to not hearing the turbo whistle like i used to, i can't see any smoke from the exhaust and i aye noticed any loss of power when driving . I aye very mechanically minded so would welcome any help in this matter. i have owned this car as a second owner at 18000 mile, i don't drive it hard either on acceleration,just normal driving i suppose.i was going to sell it but the car is really nice so don't think i can justify chopping it in.
looking forward to any help
Thank You.

[itavaltalainen]

Can you post a photo of it? Does the car use any oil?

Does it show any fault codes or do measuring blocks look suspicious? I could scan car for you with my VCDS and have a look, am only few miles off M5/J7.

[villatone]

Thank's for your reply my mate,sorry i did not get back to you till today.
just to end my post i went to midland vw at norton cane's near cannock they said nothing wrong with my turbo,and the small oil leak around the filler cap just need new cap as rubber seal failed,this seems to be a common problem.
So picking up new cap tuesday 5 july and that should be the end of my problem but will keep an eye on it for the near future.
Midland VW are excellent and can't recommend them highly enough,now i can rest easy.