back of engine oil leak

[Kdubski]

5,000 miles after rebuilding my motor, I have a serious leak from the back/top/passenger side of the motor. The whole passenger side of the transmission is wet, which leads me to believe it may be valve cover gasket half moons (made sure to RTV this) or, something else back there. Very hard to see, but looks like bottom of header flange 6 had some oil hanging off the bottom. I didn't have the time to take it apart today, but want to order parts ahead of time so I can fix it right away. CPV gasket replaced with Viton o-ring at time of rebuild.

So far, I think my culprits may be VCG or Cam Position Sensor. Let me know if anyone else has a possibility to throw in.

Thanks,

[heinzboehmer]

There's also a couple of plugs at the back of the head that some have had fall out. Worth taking a look.

[Kdubski]

There's also a couple of plugs at the back of the head that some have had fall out. Worth taking a look.

Thanks for the diagram. Got paranoid that maybe I forgot to torque one of the plugs. Turns out it's a case of the half moon's leaking...

[Cubieman]

Thanks for the diagram. Got paranoid that maybe I forgot to torque one of the plugs. Turns out it's a case of the half moon's leaking...

Did you use an OEM VCG?
I recently did some work and didn't put RTV in the half moons as I felt it would be too difficult to clean off. I ran the car hard for over 300 miles and it didn't leak at all there.
I went back in and did a bit more work last week and DID put RTV in the half moons simply because everyone talks about it.

[TexaZ3]

CPV?

[Jickel180]

Curious to what you find. I'm going through something similar, and I can trace the oil to the top of the head just below the valve cover gasket. I've replaced the CPV, Crank Position Sensor o-ring, Valve Cover gasket, and now the Oil Return Line from the head to the pan and I'm still seeing oil pool up on the crank position sensor, and then burn on the headers. It's driving me insane!

[QuickM3]

Curious to what you find. I'm going through something similar, and I can trace the oil to the top of the head just below the valve cover gasket. I've replaced the CPV, Crank Position Sensor o-ring, Valve Cover gasket, and now the Oil Return Line from the head to the pan and I'm still seeing oil pool up on the crank position sensor, and then burn on the headers. It's driving me insane!

You might have a leak from the Oil pump relief valve. Although you said its dripping onto the headers which this is below them. 11 11 1 318 185 for reference. Its in the side of the block just below the headers in back near transmission bell housing.

[Jickel180]

You might have a leak from the Oil pump relief valve. Although you said its dripping onto the headers which this is below them. 11 11 1 318 185 for reference. Its in the side of the block just below the headers in back near transmission bell housing.

Thanks, the CPV was the first thing I've replaced when encountering this issue but the leak wasn't coming from there when I got to it. Replaced it anyway for good measure.