hello

I've always had a bit of oil / sludgy black stuff in the cross over pipe on mine. I think as long as you're not belching out blue smoke on boost the seals in the turbo should be OK.

Could be breathing a bit heavy if you've got it plumbed in as per factory.

Blue smoke on start up is normally valve stem seals.

BTW. don't be too scared of having a go at the turbo yourself..the kits are pretty cheap on ebay and its only a few little snap ring on the shaft.