New rebuilt yanmar starts instantly but small puff of smoke at startup
- Thread starter CamaroMan
- Start date
3gm30, kind of blue, clears up instantly then runs perfectly.. this engine doesnt have glow plugs so it is a cold start. Leaking injector maybe? on accel its also clean maybe a super light hint of smoke for a split second.. but nothing else. Run time is only at 20 minutes so rings need to break in -
My guess as well. Bit of oil gets through the rings and there's your puff of BLUE smoke as opposed to black which a whole "nuther story.
Why not? "Rebuilt" means different things to different people. Did he install new valve guides, ream them properly, new valves, new valves seals, etc.? Don't know.
Myself, I would take the head to a pro and have all of that done. There's a superb marine engine rebuilder about 3 miles from my house! And, his prices are very reasonable, and turn around quick!
I checked all valve guides, new seals. lapped seats. Everything looked almost new so its not a valve issue. Thanks for the replies.. the motor runs beautifully and fires right up so no concerns.
I wouldn't be concerned. Give it some time. If it continues to start up easily and run great, what's a small puff at startup. Lots, not all, diesels puff at startup. I've got some generators at work that puff at startup and they continue to run fine year after year.
Same with my 2GM. A puff of grey smoke, then pretty much smokeless, so this sounds normal to me. Ignition is from heat generated by compression. It takes longer to start in cooler weather and seems to produce a bigger puff of smoke then, which makes me wonder if it’s related to how much fuel went into the cylinders before ignition, but my diesel engine knowledge is basic. I can change my oil, filters and impeller blade and winterize it. Anything else and I’m calling my mechanic.
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Except the Puff of smoke on startup.
Reason for the post.
Let it settle a bit an see.