RB25DET Possible valve seal leakage

[Sooty Skidda]

Hae fellas im new here..i gota 1990 R32 4 door skyline with a r33 S1 RB25DET engine in it..the problem i have is that i got it and it wasnt smoking...then it started a few days later (think he put stop smoke in the oil)....it smoked a bit on decell and on idle after driving and then wen u first take off heapsa smoke...then it stops wen ur driving around..then starts smoking wen u stop again....i initially thort the turbo seals were blowen...so i pulled the turbo off and it had a RB20det turbo with a chipped exhaust wheel and visible signs of turbo seal leakage...so i replaced it with a 45v4 nissan rb25det turbo with 20det actuator...so anyway wile i was at it i replaced fuel filter.sparkplugs.crank seal.cambelt.waterpump etc etc etc..done a service on it new oil and all....to find it still smokes on idle after decell...and i know the turbo is a minter only done very low kms...is this valve seal leakage or possibly a cracked valve seal or broken valve seal??? compression test shows up as 140 135 135 135 135 150 in order which is quite good id say for a DET?well not perfect but u know...it smokes on startup too....im pretty sure this is valve seals but i just want some other peoples inputs....has anyone here done a rb25 valve seal replacement with the head still on the car??

btw its alota smoke lolcheers for any help

[robbie2883]

bad piston rings can cause lots of start up smoke too. i would do a leakdown test and that will help you isolate the issue to the head or the block. if it's in the head then yeah i'd lean toward valve seals....or a cracked head.

[Sooty Skidda]

woohoo so much replies!!!! turns out wasnt valve seals at all...the so called 111k turbo i got is completely f***ed....pulled the intercooler pipe off and had oil in it wen i put it all on dry...oil also in intake...not much but still i only drove it 10km since i put it in....removed turbo to return to buyer (paid 250 cash for it off trademe.co.nz and its rooted) and wen i removed turbo i found my whole downpipe is covered in oil on the inside and the compressor housing is full of oil and my manifold is dry on the inside...definatly turbo seal leakage....i wondered y wen i got the turbo the exhaust wheel was clean and not covered in black soot...i think he cleaned all the oil off it before he sold it to me!!!!! now i need a new turbo...again.......

[robbie2883]

HAHA>.....i would have suggested turbo first but you covered that in your original post.....if there's that much oil you might want to check the oil return line and see if it's blocked in anyway. if there's some kind of blockage you might be building pressure in the bearing section and blowing it out the turbo seals