i've a remapped 535d with 91k on the clocks (although i've a feeling these miles could be alot more)

over the past few weeks i've noticed that at random times it will just fill the rear of the car with blue smoke for a few minutes. you can't predict when it will do it, it just does it randomally. like once every week or somethin.

i thought the dpf in these cars was meant to stop smoke from the exhaust (well not literally)

so today, fearing a turbo (the smaller one being most common) being on the way out, i started to check filters and pipes and stuff. i got the crankcase breather off to get a look at it thinking it may be practically blocked or in bad condition. well as i was taking it apart i broke a plastic bit off the casing putting it back together. i looked around it and it just looked like a bit of the plastic shape inside it.........being a sunday i couldn't go get a replacedment from bmw to be safe. but i screwed it all back together and started the car up. no smoke, all sounded well, etc

went for a short drive and immediately the car was slow! reluctant to rev, would take ages to get to 3k revs and not go past 3k revs. wouldn't kick down or nothing. it did kick down once and ever since that there has been a turbo whine......and still the reluctance and no 3k+ revs. no smoke out the rear and no oil or nothing in the exhauast tips

put the car in park, or neutral and it revs freely and so on. has started to make the whineing noise now though.

being a sunday......what is the dianosis before i take it to an independant? initially i was hoping vacuum pipe or some sensor or fuel filter.......but ever since the whine i'm getting worried it may be one of the turbos?

i've no warrenty and very little service history.......so i've no hope of getting bmw discount or goodwill. so i'm worried about the cost!

any help would be appreciated