fiestaturbo.com

[escortdriver1]

Confusing one..

Full Zetec turbo with not much mialage on it im getting blue smoke on the overrun, the turbo has just being rebuilt with 360 bearing, properly done and less play than a nats bo**ock

Dont get any blue smoke when full throttle so keep thinking its not piston rings, and on first start up i dont get any smoke :S
Ive been told its either rings, valve seals, blocked breather or turbo
But its a fresly rebuilt t34 turbo, very low mialage engine, all breathers are to atmosphere (crank and rocker cover) with no blocks at all and i dont get any smoke on idle :S

Its on a basemap and the head was off a unknown mialage 2.0 with origional seals but i did lap in the valves and uprate valve springs and use the frs head gasket

Ive got the tool on its way to do a compression test to just rule out rings for sure but i know there low mialage but someone else run the engine in so if it is poorley run would the compression be low on all the cylinders so i wouldnt knotice anything?

Any ideas?

[FRSJON]

did you change the valve stem seals ?

[escortdriver1]

i diddnt mate no i only changed the valve springs and lapped in the valves

[Dave5300]

Sounds like the stem seals to me mate as its not smokeing under boost

[mikeymikeyp]

usually stem seals only leak when left for a while like overnite and youll get a puff as soon as you start the car and nothing else after that ,im just wondering if you maybe knocked a spring of the top of the stem seal when u done the valves that might let a bit more oil in
They valves are a pain to get to dont know why you didny just change the stem seals

[escortdriver1]

I should have done mate dont know why i diddnt, ive done compression test and come up all the same so that rules them out, turbo been rebuilt by a midlands turbo but could the turbo be gone and it smoke on over run not on boost?

[snake]

compression test means nothing with regards to the stem seals, the oil is going through the engine via suction as its on overrun. Turbo normally blows white smoke due to high temps and normally smokes all the time and you can check the end float anyway, if its not breathing heavy then its internal engine, either rings or stem seals, chances are the stem seals would have been damaged when grinding the valves in. With regards to the rings, the top compression rings may be ok but it could have a damaged oil control ring.