willys_wonka
Member
Hey all, Ive got a Yanmar 4JH2E with unknown hours (but assume pretty high). I'm concerned about it smoking. Blue smoke, especially on start up but even when warm there's a noticeable amount. Now I've seen some boat diesels that have enormous plumes when starting and running and this is nowhere near that. I never have to add oil between changes.
Usually blue smoke means worn cylinder walls and piston rings - time for a rebuild. But this engine starts instantly - I mean instantly, even in the cold of winter. No glow plugs, just hit the starter and in a fraction of second it roars to life, like a new engine.
Now generally, worn rings also mean lower compression and a bit of grinding on the starter to get a diesel going, with a big puff of white smoke on startup. Not this engine. So what's going on? Valve stem seals will cause smoke on startup but usually not while it's running.
Ideas?
Usually blue smoke means worn cylinder walls and piston rings - time for a rebuild. But this engine starts instantly - I mean instantly, even in the cold of winter. No glow plugs, just hit the starter and in a fraction of second it roars to life, like a new engine.
Now generally, worn rings also mean lower compression and a bit of grinding on the starter to get a diesel going, with a big puff of white smoke on startup. Not this engine. So what's going on? Valve stem seals will cause smoke on startup but usually not while it's running.
Ideas?
