A.H.

Hello everyone,

This is a recently purchased, used Audi A6 3.0 L Quattro Automatic.

I discovered an extensive oil leak from my valve cover gaskets, it looks to be leaking around the entire perimeter of the both gaskets.

I removed the valve covers to replace the gaskets but discovered the old ones were in fine condition.

I did some research and found that the pressure inside the crankcase is too high. I went back and looked at my crankcase breather hoses and PCV valve. They all look very new except for the lower breather hose that goes underneath the manifold.

My guess is that someone replaced all of the easy to get to components (upper breather hoses, PCV valve and valve cover gaskets) to fix the leak in the valve cover but it didn't fix the leak so they gave up.

So the harder hose to replace is the lower one, it is clearly older than the upper hoses. I need to replace it but I cannot find anything about the PCV or crankcase breather hoses or intake manifold for that matter in the Bentley service manual. How do I go about removing the intake manifold to get to that lower hose? Are there other places I should check for blockage in the PCV system (it clearly isn't blocked in the new hoses)?

I tried to test the PCV valve by plugging one hose connection (there are 2 hose connections) and blowing through it then trying the same on the other. It seems that when I blow on either end, I cannot give any positive pressure but negative pressure (sucking) is regulated within a range by the spring and diaphragm. I think this PCV valve is working correctly.

For some reason, I am getting positive pressure in my crankcase and this is forcing oil out the gaskets. Could there be a blockage down low somewhere?

Thank you everyone for the help!

- Al

A.H.

Is there a diagram of the whole crankcase pressure regulating system anywhere?

SloopJohnB@mac.com

They also have an online version

A.H.

Is the online version different from the print version?

I found this write-up:

DIY: B6 3.0L Vacuum Actuator/Drive Unit + Intake Manifold

Do the fuel rails need to be removed to get out the manifold?

old96A4

I did this job to replace the valley pan gasket because it was leaking. Most will need this replaced soon. so you might as well get the parts when you take the manifold off. yes you have to take the fuel rails off. the whole job was pretty easy. get manifold gaskets also. you don't have to take everything off like in the post you found. There is a check valve underneath. could be plugged. use synthetic oil.. keeps the crap down. also be careful not to break the plastic hoses. but you can use shrink wrap to fix them.
I thought mine was the valve cover gaskets and it was the valley pan. I think I have pictues in one of my older post describing it.

A.H.

Thanks! I did find your post:

https://www.audiworld.com/forums/a6-.../#post24745609

I can see things look pretty leaky down there. I ended up taking off the throttle body to get to the breather tube but can see the valley pan and oil mess. My only question, where the heck do you get a valley pan gasket for the A6 3.0L? I've been looking all over online and even called NAPA.

Thanks for the help!!!

A.H.

Looks like this is the one:

https://www.ecstuning.com/Audi-C5_A6...3.0L/ES280204/

But here it is cheaper:

https://www.hansautoparts.com/06C103771-Gasket.aspx

jcman

Quote: where the heck do you get a valley pan gasket for the A6 3.0L?

Answer: When all else fails bend over at the dealership parts counter or order online from this one OEM Audi Parts & Accessories at Jim Ellis Audi Parts