Hi all,I have a 98 v70 turbo awd.just bought it a month ago with a bad engine.I replaced it with a used engine only to find the used one had a bad turbo(massive smoke) so I swapped that out and the smoking stopped within about 5 miles of driving.all was fine for about300 miles then I startednoticing an occasional puff that I thought was maybe just left over oil in the innercooler,however it is getting worse and at times can be really bad,it comes and goes,heres what I,ve noticed.Other than the occasional small puff on start up,it seems to be bad after accelerating normal, let off gas, coast a little,hit gas normal and lets out a pretty good cloud to the point that the back glass gets oil splatter all over it.plugs look good no fouling, compression is 175-178 on all cyls.there was a fair amount of oil on the top of head around plug wiresthat was not there when I did install and there is oil running down dipstick tube from top to the point its dripping off of oil pan.All else seems ok other than a small oil leak at the bottom of oil tube feeding the turbo,(already replaced the o-ring).could this be the flame trap?I am baffled by the fact its only an intermittentproblem,but when it smokes its pretty bad.thanks in advance for your help,I am selling the car as we findwe dont need it now, but I cant sell it like this.

 

I would replace the vent box and make sure all hoses are clean and clear.