Hi all

I've rebuilt a D16Z6 recently, starts first time, runs fine, but its blowing a little of blue smoke when it's warming up then disappear when reaching certain temp. And also clouds of smoke when I hit the Vtec zone.

As I didn't change the valve seals and piston rings, so I'm guessing those were not sealing properly, so I've done the compression check, (where standard should be 185psi, correct me if wrong) which all got around 180 psi, less than 5 psi different between each cylinders. didn't do the leak down test which I think i won't be able to tell me anything if its get such compressions. Checked the spark plugs as well, but they all look OK, showing grey/brown deposit. Checked the dip stick, doesn't look like if its eating oil badly..

Do u think its going be the valve seals or piston rings? or there might be something else?

Any method that I can test to see if its the valve seals or piston rings?

Any method that I can check the compression at high revs?

I'm sort of thinking it's more likely to be the valve seals. asuming oil dripping down to the cylinder over night, then smoke a bit when it starts up, then goes away when all oil has been burnt off. not sealing well at high revs? Agree??

I've done millions of search but there were all about doing compression test & leak down test. hope u guys would be able to help!

thx. in advance!

Terry

 

i would think its the valve seals they get hard over time and leak a little oil while sitting up and at high rpm's.... thats the first thing i would have replaced if i ever had my head off.....good luck

 

Is it still blue smoke at high RPM? Mine dumps out black smoke at high RPM from running rich.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civic_95_Si &raquo;</TD></TR><TR><TD CLASS="quote">I've rebuilt a D16Z6 recently, starts first time, runs fine, but its blowing a little of blue smoke when it's warming up then disappear when reaching certain temp. </TD></TR></TABLE>

blue smoke while warming up is caused by valve seals..
go search for "blue smoke".. you'll get a lot of info

 

blue smoke = oil

black smoke = fuel

 

Thanks for the info guys, I would say blue smoke at high revs, eventhough there r little black deposit, but don't seem to be oily.. so I would think is only the carbon..

 

you are getting excess blowby. if it is coming out of the tail pipe/exhaust its the rings/ringlands.

 

well, maybe I didn't explain it right, there's only blowing out black stuff only when I hit hard on the throttle, and it looks like it a mixture of water drippings (which I think is normal right?) and carbon....

Terry