Okay i had a D15B7 that had a burned out valve... when the engine was running we reved it up good and there was no blue smoke... at start up or when reved up. So anyways i took the head off and replaced the valve that was damaged. I installed a new valve (i made sure to lap it properly so it seals correctly) I didn't replace the valve seal though. Also i noticed quite a bit of carbon in the combustion chambers and on top of the pistons I scrapped all of it off and cleaned all the piston tops and valves to prevent a piece of carbon from damaging another valce. Anyways i put a new head gasket on and put it back together. Started it up and now it blows smoke on startup... and it takes a few minutes of driving before it clears up. Also if i let it idle for like 5 minutes and then rev it up hard it blows a good amount of whitish/blue smoke....

Im not really sure if its some carbon in the cylinders thats casuing the smoke. I guess ill have to drive it some more and see if it clears up.

Just wondering if you think its the valve seal from the valve i replaced???? Would 1 bad valve seal cause a lot of smoke on start up???

to replace the valve seal i heard you can pump compressed air into the spark plug hole to keep the valve from falling after removing the retainer and keepers/spring...... is there another way to do this? (like putting the piston at TDC.... will that keep the valve from falling?)

thanks... sorry for the confusing post.


this is the 4th engine i have put in my civic in the last 2 year (i get them for free) but im tired of having to put 1L of oil for 1 tank of gas.. and also smelling like burnt oil ever time i drive my civic.

 

When you change the head it will usually smoke for a while.
A bad valve seal will smoke on startup and stop eventually after driving for a minute or two.
I usually put the piston at tdc and compress air in the cyl to keep it from falling.
You could also put it a tdc and put some rope in the cyl to keep the valve from falling.
I compress sohc springs with my fingers.

 

okay... how long does it usually smoke after changing the head

(i actually just removed it and replaced the valve and then put it all back together....)

 

Just drive it around for a while and see what happends. I drove mine at night and it took 10 minutes.

 

yeah im pretty sure its not the rings.... i could still see the crosshatches on the cylinder walls... (indicating the rings were still decent)

also the old engine that i took out .... when i took the valve cover off everything looked like it was covered in oil deposits. it was just caked... the new engine i put in...under the valve cover it was still shiney looked good.

i hope i didn't mess this engine and the smoke clears up..... i really dont feel like spending another 8 hours taking this engine out and putting in another.....

 

Valve guide seals