MBC leaking

alright i searched and couldnt find an answer for this

i have a turboxs standard mbc
i did a compression test today and i had a tiny leak where the intercooler pipe connects to the intake manifold

but, i had a very big leak on my mbc. it has 2 rubber round gaskets that go on the outside ridges of it, and under one of them it has 2 machined holes in it, and thats where all the air is coming out

my question is= are mbc's supposed to leak, and if not, should i buy a new one or what?

alright i searched and couldnt find an answer for this

i have a turboxs standard mbc
i did a compression test today and i had a tiny leak where the intercooler pipe connects to the intake manifold

but, i had a very big leak on my mbc. it has 2 rubber round gaskets that go on the outside ridges of it, and under one of them it has 2 machined holes in it, and thats where all the air is coming out

my question is= are mbc's supposed to leak, and if not, should i buy a new one or what?


I have the same one, now I am curious as to if mine is leaking. But to answer your question no they are not supposed to leak.

Try

http://www.joepmbc.com/

Good MBC's for a good price

I think I might pick one up as well. I have a feeling this MBC might be the cause of my boost problems.


In fact as I wrote this I bought one.

If anyone would like my old turbo xs one send me a pm and You can have it.

My Turboxs boost controller leaks too and I thought about buying a JoeMBC. Maybe they are supposed to let air off to control the boost? Although mine wouldn't change the boost at all so its pretty pointless.

Hmmmmmm.... leaky Turbo XS BOV's and MBC's? Red flag there, thanks guys. I would have to second the JoeP MBC, Mike got one. Hes a nice guy and great product. Thats whats going on my DSM when I get one.

I believe the Turbo XS MBC's are bleeder valves, so they bleed off boost to raist boost levels. You want a ball and spring type of boost controller, such as the JoeP.

I have a JoeP and I don't creep at all, even with an unported evoiii. Very good and cheap BOV

All modern MBCs are ball and spring, including the turboxs. They will also ALL have a hole between the valve and the wastegate actuator. It's there so the WG can close ;)

All modern MBCs are ball and spring, including the turboxs. They will also ALL have a hole between the valve and the wastegate actuator. It's there so the WG can close ;)

So that means our TurboXS MBC's are supposed to hiss like that? If that is the case, do ball and spring ones have an advantage over traditional MBC's?

Yes, ball and spring units are better than bleeders, mainly because the ball/spring valve stays closed until the set boost pressure is hit. This make them tend to spike more, but a prper spring rate and other variables can limit it. Turbo XSs are known for spiking more than Halmans or Joe Ps. I like the Joe P personally.

The hole is supposd to be there, and it will leak during an intake pressure test. I usually block off the MBC when testing so it doesn't make it hard to find the real leaks.