It feels like its coming from the top of the header between the two pipes directly on top of the RB thats cut out of the header. First I had tried doubling 2 old gaskets I had and it leaked in same spot, then when my new gasket came I put it on and same spot leaked. Header flange is flat and not warped in any way. Is there a reccomended sealant to use? Anyone else have this problem before?

 

I pulled the lower intake manifold so I could see how the header was sitting against the engine and I found the problem. The S4 LIM Im using doesnt block off a small exhaust passage directly under the intake holes on the center iron of the S5 motor. So Im going to swap a S5 LIM on there. Does it flow better than the S4 one?

 

Probably not as most of the changes on the intakes between series were in the dynamic chaber and VDI - it *might* but chances are no.


thats even if its a direct bolt on......but I have no idea since you don't really say exatcly what you have....

 

Its a s5 block, it leaked with the s4 LIM on it. The bottom of the S4 LIM doesnt cover the exhaust passage on the center iron completely because on the s4 motor there is no exhaust passage. I did the swap and fixed the problem. You could tell right away if you look at the two LIMs one has a square hole one doesnt.
BTW they are direct bolt ons