Fresh build, smoke on startup then disappears

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airman
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Fresh build, smoke on startup then disappears

Post by airman »

As the title states, my freshly, fully built KA24DE blows what is now a small cloud of smoke over a period of about 10 seconds during startup. It looks white when it first comes out (could be the few ounces of seafoam I put in the crankcase with the oil change) and then goes bluish as it gets less dense until it finally goes away and won't come back during driving/idling/etc. It only happens when it is cold. It has started doing this over the past week or so and is getting worse, though the car runs great otherwise.

I'm familiar with this issue as it typically involves the valve seals but the head is fresh too. I didn't do it myself, I had a machine shop deck it, grind the valves, and put in new valve seals. Is it possible it's just a shiddy job? I've had several things done with this guy over the years and he seems to do good work, but I don't know...

Compression is good and still rising as it's breaking in, i think it's at about 170psi right now warm across all cylinders if not higher. I haven't checked it in about 60 miles or so.

Head gasket should be fine as coolant and oil are definitely separate, I observed this last week when I changed oil and drained coolant to put in a thermostat. I have seen the temp gauge at the notch before the H (showing like 245f or so in Nistune) for no more than 15 seconds before I shut it down (facking gay Stant thermostats...pieces of junk) - which has occurred probably 5 times but I don't think that would cause any issue.

During the initial tuning stage to adjust for my 85lb injectors N/A, I knew it has run rich during cruise and idle which I have since ironed out, but I don't think that would affect anything.

Any idears?
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sicks13
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Post by sicks13 »

I would say you need more time for the rings to seat..
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airman
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Post by airman »

It didn't do this originally, it's gotten worse - quite bad actually. I've never seen a "fresh" motor cough that much oil on startup.

Would you think the cylinder walls have glazed from running rich for a short period?
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Kfred
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Post by Kfred »

Could be valve seals.

I would continue driving it and see if it clears up. I just rebuilt my daily and it was smoking really bad on startup. It finally cleared up after 10k miles. I did a **** backyard hone job which was probably my cause.
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Jordan Gladman
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Post by Jordan Gladman »

If you can pull your intake manifold off your motor - cold. You can check and see if oil is puddling on the intake valves. When my stem seals were bad, there would be a sizeable amount of oil sitting on the valves ready to go into the cylinders on start-up.
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airman
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Post by airman »

Jordan Gladman wrote:If you can pull your intake manifold off your motor - cold. You can check and see if oil is puddling on the intake valves. When my stem seals were bad, there would be a sizeable amount of oil sitting on the valves ready to go into the cylinders on start-up.
That's a pretty good idea. I'll give that a look.

Kfred, how much did it smoke? Like I described it's a pretty good-sized cloud.
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Kfred
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Post by Kfred »

airman wrote:
Jordan Gladman wrote:If you can pull your intake manifold off your motor - cold. You can check and see if oil is puddling on the intake valves. When my stem seals were bad, there would be a sizeable amount of oil sitting on the valves ready to go into the cylinders on start-up.
That's a pretty good idea. I'll give that a look.

Kfred, how much did it smoke? Like I described it's a pretty good-sized cloud.
Pretty nice little plume. Enough to be embarrasing
RIP Nate(480sx)...
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airman
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Post by airman »

Yep, that's how mine looks/makes me feel :(
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