Puzzling development - thoughts please!

Am putting this in here now as it spent a week or so in Technical without much response!!

For those who don't know the story of my pride and joy it had a nicely rebuilt engine fitted about March/April this year with +1mm forged CP pistons etc, refurbed tubbies, new stem seals - the works in fact! Bundles and oodles of cash etc etc!!

Now the new engine has about 6K under its belt and is nicely run in. A new query has raised its head though. Sometimes whilst idling in traffic I'll get a whiff of oil in the car and, a minute later, a nice cloud of smoke out the back! This doesn't happen all the time.

It happens most though when I slip the car into reverse and move ever so slightly - this seems to release a lovely cloud of smoke! The theory is that oil is collecting somewhere within the breathing system and occasionally being drawn into the engine - Suggestion 1 is to fit a catch tank to see if oil is being drawn into the breathing system or not. After that I'm not sure what to check!!

Have any of you encountered this problem of oil in the breathing system before or fitted a catch tank for this reason?

Thoughts and suggestions appreciated!

Piston rings have been ruled out!!!

seeing as its at low revs (starting to reverse etc), i don't think a catch can will do any good (easy to install a temp one to find out though).

make sure you pack it with stainless mesh, this makes them more effective at "catching" the oil mist

Will do - cheers mate!