Fresh build, smoke on startup then disappears

Basic tech questions such as future setups, different turbo kits, car diagnosis, etc
Post Reply
User avatar
airman
KA-T.org OWNER
Posts: 2137
Joined: Tue Jun 16, 2009 12:51 pm
Location: Anderson, SC

Fresh build, smoke on startup then disappears

Post by airman » Thu Apr 14, 2011 9:49 am

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?

User avatar
sicks13
Dont Question My Nissan Knowledge
Posts: 607
Joined: Wed Oct 11, 2006 12:56 pm
Location: W.N.C

Post by sicks13 » Thu Apr 14, 2011 10:07 am

I would say you need more time for the rings to seat..
Image

User avatar
airman
KA-T.org OWNER
Posts: 2137
Joined: Tue Jun 16, 2009 12:51 pm
Location: Anderson, SC

Post by airman » Thu Apr 14, 2011 10:28 am

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?

User avatar
Kfred
Belongs To The TOP CONTRIBUTING MEMBERS!
Posts: 3513
Joined: Sun Oct 29, 2006 8:12 am
Location: Baton Rouge, LA

Post by Kfred » Thu Apr 14, 2011 10:47 am

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.
RIP Nate(480sx)...

User avatar
Jordan Gladman
Belongs To The TOP CONTRIBUTING MEMBERS!
Posts: 3254
Joined: Tue Jul 20, 2004 11:14 pm
Location: Abbotsford, BC

Post by Jordan Gladman » Thu Apr 14, 2011 11:18 am

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.
WWW.GLADFAB.COM SOHC Turbo Manifolds

User avatar
airman
KA-T.org OWNER
Posts: 2137
Joined: Tue Jun 16, 2009 12:51 pm
Location: Anderson, SC

Post by airman » Thu Apr 14, 2011 12:22 pm

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.

User avatar
Kfred
Belongs To The TOP CONTRIBUTING MEMBERS!
Posts: 3513
Joined: Sun Oct 29, 2006 8:12 am
Location: Baton Rouge, LA

Post by Kfred » Thu Apr 14, 2011 12:28 pm

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)...

User avatar
airman
KA-T.org OWNER
Posts: 2137
Joined: Tue Jun 16, 2009 12:51 pm
Location: Anderson, SC

Post by airman » Thu Apr 14, 2011 12:41 pm

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

Post Reply