Where is my blowby coming from?

[Kyle97turbo]

I am getting some pretty bad blowby heard through the valve cover when I do a boost leak test. I disabled the pcv to rule that out and was still getting the blowby. Could a leaky compressor seal on the turbo be causing any of this? Its an evo3 16g that I just rebuilt. If not whats some other possible areas I should start looking at?

 

[CrazyM]

You have a MBC? Mine was trippin' me out for awhile. There is usually a hole drilled into the side of them that will always leak.

 

[canada4g63]

My guess would be the seals on the turbo

 

[rush2252]

Do you have the intake cam in position so that all 8 valves are closed?

 

[habitatguy187]

Do the leak from the TB elbow and see if it's still happening, if it's not, then it's the turbo seals, if it is, then it could be leaky intake valve seals, piston rings, headgasket. I think that's it.

 

[MichaelSuch]

Put a wrench on the crank and turn it clockwise until it no longer leaks, you probably have intake valves open still, allowing air to rush through the motor.

 

[DSMunknown]

Do a compression and leak down test.

 

[habitatguy187]

Put a wrench on the crank and turn it clockwise until it no longer leaks, you probably have intake valves open still, allowing air to rush through the motor.

Even if the valves are fully open it shouldn't pressurize the crankcase. Hopefully it's just a bad turbo seal.

 

[Kyle97turbo]

Yeah I will be doing a blt from the throttle body tonight to check if its the turbo. After that ill try the comp test and leakdown test. Compression should be fine it was 170 on all four just a few weeks ago and I haven't really drove it since then. Hoping for bad turbo. Also doesn't burn any oil or use any coolant.

 

[DSM1G90]

?valve seals?