Got your email.
No restriction in my oil feed line, there was a mass-debate about it and some did, some didn't but on the whole you shouldn't need one, especially at tickover where oil pressure is low anyway.
Some people suffered oil blow through at higher revs/pressure and used the restrictor then.
If it's pissing out on just tickover something is wrong with the turbo/seals/shaft etc.
Know you have the H1C "how to guide" I sent you, you can rebuild the fecker yourself!
HTH, Mark.
