Thread: Boost leak?

I got my car all together and hooked up the wideband etc. This is a VE with GTIR T28, bb manifold, yellow STI sidefeeds, Calum RT, running 7psi. I just took it out for another run to try to tune it. Adjusting the fuel is barely effecting anything. So I am in the garage right now doing a leak down.

When I pressurize the system, a very little bit of air steadily flows out from the valve cover hose. When i plug the hose for a couple seconds then release it, the air comes out in a burst, like it is seeping into the crankcase or something. Anyone have any ideas what could be causing this?

I have the PCV vented to atmosphere and blocked off the hose to the IM. Also, once i get up to 10psi or so, a teeeeny bit of air leaks out around the butterfly valve shaft on the TB. These are the only places I can find that are leaking any air.

Here's a pic of the engine bay where the trouble areas are.

anyone? Suggestions?

What happened with the leakdown test? That should have told you, or did you mean just boost leak test?

Do you have any lines going into the VC? The one that is circled you plugged that right?

You might have an intake valve not sealing IMO.

PCV and the VC tube (which are both circled) are both open to atmosphere. The boost leak test seemed to do well. None of the pipes or couplers leaked at all. The spot circled on the TB gives a verrrry slight hiss at about 16psi.

I also have a question about my MAF The number on it says AFH70-16A. Is this a VE MAF or not? because I thought VE MAFs were good up to ~300hp. Mine is hitting ~5.05-5.09v in the higher RPMS (7000+). I have my ECU setup for the VE MAF, so if this isn't it, this could be my issue.

That pic looks like you are pressurizing the valve cover. That hose should be connected to your intake pipe for vacuum. You should also reconnect your PCV valve.

The PCV lets air by (in the wrong direction) so the hose to the IM is blocked off. The hose from the VC is not connected to the IC piping. It is just open to atmosphere.

Dude get that hose off of the intercooler piping asap man!!!!!!!! That needs to go on the intake pipe on the turbo as Naghebe said also.

Oh sorry just read your post well that hose needs to be connected to the intake on the turbo

The PCV closes when you're in boost, and when in vacuum the PCV opens, allowing that grimey crap out of the crankcase and into your intake for reburn. The hose on the VC should be run to a catchcan of some sort, or run back into the pre-turbo intake piping.

When pressure testing, a very little bit of air should come out of the valvecover regardless, because not all intake valves are open.

You should pressure test the system much higher than it seems you are. Easier to check for leaks when you pressure test at 30~35psi, vs. 15~18psi.

Use a long piece of vacuum line as a stethoscope to listen for leaks in areas you can't normally reach with your fingers (around the injectors and whatnot).