ROG100

We sell Behr or Wahler thermostats and they come with a seal, hower it is useless so we take it out and throw it away and replace with the correct seal.

ChuckD

I have the Wahler and it does indeed fit nicely and nearly clicks into its spot. So what might be a logical place for oil to leak into the valley. Where should I look? Thanks all!

ammonman

Usual suspect is the seal between the oil filler/separator and the block. Could also be a bad crankcase breather line. Probably easiest to change this seal while the water bridge is off. Apply a generous amount of aluminum safe silicone like HondaBond/Yamabond/Driebond to the seal and filler base before installation. Allow to cure well before start up.

Mike

Landseer

One leak prone spot on 16V cars is where timing gear backing covers, mickey mouse ears, contact the heads. There are O rings there. Usually they leak down along front edge of head, then around corner down length of head / block interface, giving illusion of head gasket oil leak. If leaking badly, oil could blow and collect in valley. These I always replace on a 16 V car when changing cam end seals.

Another spot is simple spillage or hose leakage in/around the fill canister.

Another is oil carrying into vac line for booster and the line breaking down and leaking over time.

Lots of sources, one approach is clean it all out and keep eye on it.