Ploblem with AAN

[Roer_S]

I have a problem I need help with!
My new build engine (AAN) is breathing oil in the head breating (behind the head) when I use the engine hard. It is a lot off oil.
The oil breating in the block is perfect and as it should be.
I have checked the cylinder compression and its the same all over! so no broken piston rings.Oil pressure is good also!

any ideas?

[Knight Rider S4]

Do you mean there is a leak at the rear of the head?

[Knight Rider S4]

If it is first place to look is at the back of the cam cover and check the seal round it especially the half moon seals at the end of the camshafts they are the worst for leaking

[Pirvu Eugen]

You have check the valve from the breather tube if is conected right or iff is working ok?
Maibe att full throtle the the valve is not working and the oil vapors are going too much in the turbo.
Just an idea!

[Roer_S]

its not the gasket, the oil comes from the little tube in the back of the cam cover.
I have no valve just open in both ends

[kwlw]

its not the gasket, the oil comes from the little tube in the back of the cam cover.
I have no valve just open in both ends

Where are you venting fumes to? To atmosphere, or to intake? If to intake - both valves (small to intake manifold, and bigger to the head) are mandatory.

Sau

[Roer_S]

Both goes to atmosphere!
I am just thinking, can the head cracked when i tight the bolts? I used the corect moment and avery thing!

[s2_bo]

Do you mean its leaking oil where a pipe like this should normally be:

camcover.jpg

If thats the case then thats one of the connectors for the breather system. They should not be left open or blocked off as far as im aware.

If you haven't got the PCV system installed then you should really be running a breather or catch tank to stop oil splutter etc.

[UrS4boy]

The oil breating in the block is perfect and as it should be.
any ideas?

Things are NOT perfect as they should be. You are missing parts from the crankcase ventilation system. I think you really need to have a look at this:

http://forums.audiworld.com/s4s6/msgs/152686.phtml

Should help.

[Roer_S]

I understand but I have run like this before the engine was rebuild and it was no problem then?

[UrS4boy]

I understand but I have run like this before the engine was rebuild and it was no problem then?

Assuming there are no problems with the rebuild, you now have a) more compression and b) more vacuum (with throttle closed) than you had before. Both of which could potentially impact the ventilation of the crankcase. In my country, you can not vent the crankcase to the atmosphere, it has to go to the intake air. All I can say is I think you should install the proper OE crankcase ventilation system.