??major boost leak, you will never guess where it came from
 

my blow off valve. i dont get it. its weird. the vacuum lines are all right as far as i know. for some reason it leaks boost, then shuts under vacuum, i think. is it just a bad bov? btw, its a pos bosch bypass valve, the same ones that are on mustang SVO's. thanks in advance for any help.

Re: ??major boost leak, you will never guess where it came from
 

you think?
are you standing by the engine?
most stock bypass valves leak at idle. if you give it some throttle, it will close.
you will have to build up some boost to make sure it is working. does it build boost when driving? and do you hear it when you let off the gas?

Re: ??major boost leak, you will never guess where it came from
 

im not sure that it is leaking boost. no, i do not build boost, and that is the only thing i can think of, unless my boost gauge is fucked up, which is possible. when i put my hand over the valve and rev it, it blows air out...

Re: ??major boost leak, you will never guess where it came from
 

the bosch ones have a rubber valve which can tear and cause boost leak.
plug the hole and see if you build boost. don't over do it. or try another boost gauge first to rule that out.

Re: ??major boost leak, you will never guess where it came from
 

A friend of mine had a Bosch bov and it lasted him 2 weeks running @5 lbs boost then it started leaking. They are not worth the money and labour.