looking for a bit of advice, sorry this is long but theres a few innacuracies with the symptoms

 

first off the dipstick seems to pop out at anything above 5k rpm but only on boost not when car is sat , when sat at idle i can rev all the way to 7k rpm no problem, second check was opening the oil filler to see if there was gas coming out and there is , not a lot though, but not all the time , if i give it a nice hard rev let it settle again there is no gas out of the oil filler, top end was rattly this morning sounding like stuck lifters , gave it a nice hard revving and the rattle goes away and so does the gas coming out of the oil filler.

 

I first off was edging towards blocked pcv valves as i know they were, then i thought rings gone as the gas out of the oil filler, then with the rattly top end i thought either stuck lifter or vtc spring worn but wondered if the vtc spring was worn as well as stuck pcv valves would this be enough to pop out the dipstick on boost and give oil out of the filler but only some of the time......im puzzled on this one, it starts fine as always and im gonna get a compression check done but any ideas welcome

get a comp check done as the only way the dipstick can blow out will be crankcase pressure mainly caused by worn rings

 

Paul