just did a leakdown test on my engine (b16a2) after having problems burning oil and missfiring. engine is normally aspirated, and have been searching for the problem before going turbo. results are as followed.

cycl. #1 has 10% leak, noise can be heard in crank case through oil cap, plug has slight carbon build up.

cycl. # 2 has 8% leak, same noise in crank case, plug is fine

cycl. # 3 has 12% leak. #3 is the one i have been having problems with fouling plugs with oil and carbon build up. oil can be seen on top of piston, and the leak can be heard and felt through cycl. # 1 spark plug hole.

cycl. #4 has 9% leak, same noise in crank case as # 1 &2, plug looks fine.

a compression test as of last year showed up ok all were about 185 to 190, except #3, which was low, about 175 or 170. i believe i found where the oil is going and the issue, but what exactly is the problem, headgasket? maybe?

thanks for the help
Jake

 

i think 20% leak is the max. well, your compression on cylinder # 3 is not bad either. i'll say is your valve seals.

 

how much oil are you burning?

 

so where is the leakdown leaking to? do you hear it coming out of; dipstick hole, radiator, exhaust ports, intake ports?

you have to listen to the leakdown to know where your problem is.

leakdown wont show you if your valve seals are bad..lol

 

the noise is coming from the spark plug hole of #1, this is the bad cycl. (#3). so when i pressurize cycl. # 3, it leaks into cylcl.#1. i can also feel the air leaking. all other cycl. i can hear a hiss from the oil cap. when it burns oil, which the problem seems to come and go, it burns alot.

 

take the exhaust manifold off and see if any of the valve guides are wet. can do the intake as well

 

if they are wet, does that mean the valve seals are bad? i will do this later this week and just trying to get some answere of what i can come to as a conclusion if i do see that they are wet. what would cause the air to leak out of cycl. #1 ?

 

A leakdown (or compression) test isn't going to tell you anything about the oil control rings, just about the condition of the compression rings. You may still have faulty oil control rings even though your compression rings are OK.

 

If you have oil on top of the piston then either
A: you have bad valve seals, or
B: blown head gasket.