Holden vr v6 engine issues

[Jarrad/vr]

Hi everyone, got an issue with my vr v6
I’ve had the problem for a while, it burns oil and blows grey type smoke when at full operating temp. Usually blows out from stop to start, sometimes it will puff out while idling in drive, so I ended up replacing the motor, not sure on how many kms it has but now it’s still doing the same thing and it’s got me stumped, would it really be my luck to get two dud engines or is there another issue causing it? I’m not really mechanically minded, don’t get me wrong I can service and change my spark plugs and stuff like that but don’t really know much big engine stuff
Another issue is now matter what I change I still get random misfires, I’ve changed the plugs and leads, brand new coil pack and dfi plate, brand new map sensor and still nothing. Help would be much appreciated guys thanks

 

[ephect]

Sounds this the piston rings aren't sealing any more. Which means the bottom end out to remove pistons, honing the boresand new rings.

Not cheap thou

 

[harrop.senator]

How long since you've changed the motor? I reckon the cat and mufflers are oil smoked from the old motor. Just how much was it burning n for how long?