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I did a pressure test the other day, and since the car has been running fine I didn't really expect to find any leaks. Boy, was I wrong!

I found two leaks by the intercoolers which was quite easily fixed. I also found one at the left aluminum pressure pipe (going to the throttle body). This one was more difficult and I actually had to change the gasket to get it fixed.

But there is also a fourth leak coming from the back of the engine somewhere that I cannot locate, not a big one but nevertheless a leak. There is also a fair amount of air coming out of the breather pipe. I can still get the pressure up (I usually go up to 15 psi) but it drops in 15-20 seconds to about 5 psi. So now to the questions.

I read the spider hose on the S4 is a usual problem when it comes to leaks. Does the RS4 has the same type of spider hose as the S4 or is the construction different? The air is actually coming from that region in the back. Please, could anyone with ELSAWin just put up the drawing so I can see how the hoses are going?

How much air is really supposed to come out of the breather pipe when doing the pressure testing? Is what I have normal or is it too much? As I understand there are some "one way valves" that are not uncommon to leak. Could it be one of those?

/Niclas, RS4 B5 2001

If you have that much air coming out of the breather, sounds like one of your one-way valves has gone. I had this problem on my S4 and replacing these cured it.

Think there may only be 2 of these on the RS4, as there is one on the S4's F-hose (which the RS4 doesn't have).