A friend of mine recently had his KA24 fully built, it has 4,000 miles on it (properly broken in). He was changing his oil today (last oil change 1,500 miles ago), and noticed that only 2 quarts drained out, but he had put in about 4 quarts during the last oil change. I followed him and he got on it, and there was some dark grey/black smoke coming out of his exhaust in 1st and 2nd gear, but not on the other gears. There are no leaks anywhere on the outside of the motor. Where is the oil being consumed? THanks in advance for the help!

 

piston rings are probably the cause,do a compression test on the motor and see where your loosing pressure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by integraswtrde &raquo;</TD></TR><TR><TD CLASS="quote">piston rings are probably the cause,do a compression test on the motor and see where your loosing pressure.</TD></TR></TABLE>

The motor has perfect compression in all cylinders

 

"there was some dark grey/black smoke coming out of his exhaust in 1st and 2nd gear"
your definitely burning oil,what about valve seals? most honda always burn oil,even new motors.but 2 quarts is alot.how many miles did he drive it before oil change?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by integraswtrde &raquo;</TD></TR><TR><TD CLASS="quote">"there was some dark grey/black smoke coming out of his exhaust in 1st and 2nd gear"
your definitely burning oil,what about valve seals? most honda always burn oil,even new motors.but 2 quarts is alot.how many miles did he drive it before oil change?
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It's not a Honda motor, but that doesn't really matter since he's looking for a more general answer as to where to oil could go. Dark grey/black smoke usually means the car is running rich. I would expect smoke with a blueish tint if it was burning oil. Bump for ideas

 

i take motors apart everyday.i can rewire your entire car back and forth.i only gave you my opinion.good luck

 

Dark Grey/black smoke means it is running rich, you are correct.

However, since it is on a new engine build, I can only assume the rings have not seated properly. This could be due to a washing down of the cylinder walls during break-in caused by a very rich condition. I have seen this many times, especially on older carbeurated cars. It is unusual on fuel injected engines as the A/F is metered much more precisely.

As long as you are running rich, you will have a difficult time to get the rings to seat.

Your friend will have to get his A/F correct before he can fix this. Once he is running proper A/F mixture, it will be easier to physically see what is actually in the exhaust gas.

Here is an additional thought.. Since it seems to be happening only in 1st and 2nd gear (Higher revs) you may be running so rich at those times that gas is mixing with the oil, thinning it out. And you are only getting blow-by at higher revs. That is a possibility, I guess.

Either way, too rich = no good on a daily driver. Just like too lean = no good.