I was in the process of removing the stock air filter hose to connect up my homemade boost leak testor and noticed that there was oil in that hose. It seems like it is coming from the hose that connects to the top of the engine. It looks more like residue as opposed to some sort of leak. Is this normal?

On a different but similar note; am I attaching the boost leak testor to the correct spot (turbo intake)? It seems like it isn't right because I have to disconnect the air filter hose which as the bov connected to it and that's one of the areas that I am supposed to check for air leaks. Thanks for your input.

 

That's why people use catch cans.

The BOV should hold if it's strong. If not, then you need to cap it off.

 

I've always wondered what the catch can was. I've noticed the bov also has some oil in it. By capping it off I'm assuming you mean the hose that is coming from the top of the engine into the air filter hose? What is the purpose of this hose, warr?

 

After doing some reading I found out that the hose goes to the PCV. If getting oil into your intake and turbo is a bad thing then why did Mitsu put that hose there?

 

Because they're not allowed to let it vent into the atmosphere.

I was talking about capping off the part of the BOV that connects to the MAF pipe, becuase obviously the MAF pipe will not be there during the boost leak test, since the tester connects to the turbo inlet.

 

Thanks for clearing that up.