About the thousandth Rebuilt engine burning oil question...

Frankensteinteg

New Member
Hey everyone,

I know that this topic has been beaten to death, I have searched the other posts, but i cant find exactly the problem with burning oil that I am having listed.

My rebuilt B18B1 is smoking quite badly, enough to leave a decent cloud of blue smoke behind me when the light turns green at the intersection.

I have only put about 100 miles on the engine since the rebuild, and have been breaking in the engine by beating on it fairly hard, not hitting the rev limiter, but still racing around. First oil change was done after 50 miles, the next will be 300-400 miles. Oil consumption is a little hard to judge seeing as how early i did the first oil change...it was down to about 1/4 from the full mark on the stick after 50 miles.

I have not yet done a compression test, but am curious as to why it will burn oil after i let off the throttle when reving it as well (vacuum sucking oil past valve seals?), and why it seems to stop burning oil (visually) when the engine gets to operating temp, even when i rev the engine. and let off the throttle?

I rebuilt the engine myself:
-New PCV valve
-New rod, and crank bearings
-New piston rings (NPR), on old pistons (measurements were within spec), ring gaps installed 180 degrees out from the next, cylinder cross hatch redone with a Flex Hone at this time as well.
-Cylinder head was professionally rebuilt, with new stem seals, valves ground, and hot dipped. Guides were ok. Head was decked/planed. Cost a pretty penny too...:???:

Engine seems to run fine; has power, and doesn't seem to sputter, idles fine.

I pulled out the spark plugs, they are a little fouled, but not wet with oil, but the tops of all 4 pistons are black with what looks like oil.

Should I put some more miles on it before I make the call on what to do? Any ideas about the issues im having will be greatly appreciated.
 
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Muckman

Not a M0derator
Yes but did you get new guides or just new seals?
Worn guides causes the valves to wobble and thats why the seals leak.
If the engine is smoking on decel then its always leaking from the head (guides/seals).
If its smoking under load then its rings.
 


Frankensteinteg

New Member
The guides were inspected by the shop, and were deemed good. New guide seals were installed at this time. Thats not to say that they didnt put the wrong seals, or installed them incorrectly mind you...

I had a friend rev the engine for me, and it seemed like only after he let off the throttle, then it would smoke. But that being said, when i take off at a light, i can see a little cloud of blue smoke in my mirror. I had it running today, and it was smoking quite a bit at idle, but once i drove it around, and got it good and hot (up to operating temp) it seemed to stop burning oil.

I really dont want to have to pull it all apart again to replace the rings or something...A compression/leakdown test should answer that question though.

Do you think i should keep driving it to see if the problem starts to go away, or do you think that there is a problem present?
 

JustinMcGee1

I like Hondas
Obviously there is some oil leaking, from the black piston heads I would assume it is mixing with the fuel past the piston, therefore oil is getting burned with gas. Hopefully that helps

this post was made in china using Taptalk2
 

Muckman

Not a M0derator
Based on your two examples it sounds like its leaking from the head (valve seals). Try another test - have your friend drive behind you and look for smoking oil when you either accelerate (Do a 2nd gear pull) and then do a decel from that speed in gear at 0 throttle. If its smoking on the decel then its def leaking oil from the top.
 


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Frankensteinteg

New Member
Ok, ill give that a try this week. Seeing as the oil burning seemed to lessen/stop when it was at operating temp, do you figure i should do this test when its cold?
 

Muckman

Not a M0derator
Whenever it smokes the most to make the test easier to see. Any leaking will lessen with temp as things expand but the issue is still from the same source.
 

Frankensteinteg

New Member
Just did compression test. Tested after driving the car for about 20 mins.

#1: 161 psi
#2: 162 psi
#3: 165 psi
#4: 160 psi
Seems like decent compression to me so far until the rings fully seat.
This time i could only notice it smoking a bit on cold start up for a mile or so, then it seemed fairly minimal; What i suppose im trying to say is that it did seem less noticeable this time around. I strapped my camera to the rear pointed at the exhaust to try and see when the smoke was occurring exactly, it did seem when it was under power, but only when the car was stone cold. after that, it doesn't seem to smoke a bit for the rest of the drive (mind you, its hard to see the blue smoke with the pavement rushing by.

On a side note the 2.5" exhaust with test pipe instead of a cat, and a 5zigen muffler is way too loud. haha.
 
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