How can you tell if your have compressor surge or BOV leak?

UHATEIT

Member
:
2008 Mazdaspeed3 Sunlight Silver
I was wondering, seeing as how there are so many thrads about shims/washers/springs being added to BPV and also on adjustments of the valve, I was wondering how to tell if you are getting compressor surge or leaking bov?

I was wondering if it can be told by looking at my mechanical boost/vac guage to read the psi when driving or by looking at me mechanical Air/fuel ratio guage as well.

I just want to make sure I'm not hurting my turbo or loosing mpg by having a leak or the wrong adjustment.

Any imput would be great!
 
to test for bpv leaks. pull off the end of the bpv hose that connects to the intake manifold. then with an air compressor equiped with an inflator for intertubes and whatnot pressurize the bpv. make sur ethe air is regulate too. you dont want anything more than 30psi. if there are leaks you will hear it....like my stocker !
 
how about compressor surge? You and I were talking before about the greddy type s and I have the fake imitation one. Just wonde4ring if I have adjusted the screw too much or not as I also did that single spring mod you mentioned. Just want to make sure It's not too tight and hurting my turbo, or too loose and wasting gas and leaking at freeway driving.
 
well it can never be "too loose" the spring holds it shut. also when under vacuum the vacuum pressure actually pulls the vlave shut. the only way it would leak is if the diaphram inside is torn which is a well know greddy problem. compressor surge sounds like a squeeky flutter.
 
how about compressor surge? You and I were talking before about the greddy type s and I have the fake imitation one. Just wonde4ring if I have adjusted the screw too much or not as I also did that single spring mod you mentioned. Just want to make sure It's not too tight and hurting my turbo, or too loose and wasting gas and leaking at freeway driving.

any pics or videos of ur type s setup?
 
if your vac/boost guage is either not going to the psi it usually does or if at idle the vac is lower than normal you know you have a leak. the compressor surge if it is anything like the msp will sound like a really loud bov flutter or a turkey gobble/pigeon cooing. compressor surge should be a universal sound, if you want to know if you have it listen to this, if it sounds like that then you may have compressor surge:

http://www.youtube.com/watch?v=3T1qDp176FI
 
any pics or videos of ur type s setup?


this is a picture of it. it's the ebay immitation type s bov on the atp adapter flange. I hoped for the greddy whistly sound but its more of a type rs whoosh sound.

3087711_24_full.jpg


Haven't taken a video of it, but I should make one to have you guys hear it.
 
if your vac/boost guage is either not going to the psi it usually does or if at idle the vac is lower than normal you know you have a leak. the compressor surge if it is anything like the msp will sound like a really loud bov flutter or a turkey gobble/pigeon cooing. compressor surge should be a universal sound, if you want to know if you have it listen to this, if it sounds like that then you may have compressor surge:

http://www.youtube.com/watch?v=3T1qDp176FI

i should make a video, it's not turkey like that its a subtle but firm whoosh that doesnt last for a long time. The vaccum idles at around 22 when idling and the when driving around normal on the freeway its about 10-12. Fr my afr guage i did not get the led digital one this time and this is my first with the needlepoint type, but it is usually around 1-3 bars rich on freeway driving, not sure what that means in numbers wise. Maybe the MS CAI makes it richer too?

this is a youtube video of someone with one of the fake ebay type S bov on it. This is pretty much what mine sounds like only louder due to more boost and louder when driving:
http://www.youtube.com/watch?v=ytjIH7gIpEs

tell me what you think about that one if that sounds bad or turkey at all?
 
Last edited:
I dont think it sounds like surge at all, doesnt sound like a leak either. if your s sounds exactly like that i wouldnt worry, differnt bovs make different noise, that reminds me of the forge bov, that makes the same type of noise since it just lifts to release air instead of having the air go through fins of any sort (at least that is what it looked like in vid) your vac reading sounds right, do you have a dedicated vac line for the bov?.
 
I dont think it sounds like surge at all, doesnt sound like a leak either. if your s sounds exactly like that i wouldnt worry, differnt bovs make different noise, that reminds me of the forge bov, that makes the same type of noise since it just lifts to release air instead of having the air go through fins of any sort (at least that is what it looked like in vid) your vac reading sounds right, do you have a dedicated vac line for the bov?.

I am using the stock vac line but for my boost guage I used a T and one part goes to the boost/vac guage and the other one it a piece of vac tube that came with the bov and I cut about 6-8 inches and made that go to the top of the bov.

Surprisingly enough the fake type S doesn't sound too bad. It's just not high pitch whistle like the real greddy. I dislike the forge myself because of the "ding" sound it makes. For the $50 it cost me for the fake greddy and atp adapter flange for it combined, I think thats a decent price to pay for ok sounding bov!
 
I am using the stock vac line but for my boost guage I used a T and one part goes to the boost/vac guage and the other one it a piece of vac tube that came with the bov and I cut about 6-8 inches and made that go to the top of the bov.

Surprisingly enough the fake type S doesn't sound too bad. It's just not high pitch whistle like the real greddy. I dislike the forge myself because of the "ding" sound it makes. For the $50 it cost me for the fake greddy and atp adapter flange for it combined, I think thats a decent price to pay for ok sounding bov!

it might help to run a dedicated line for the bov itself because the more vacuum pressure you have for the bov the better it runs, by t'ing that line for the boost guage too you take away vacuum for the bov
 
it might help to run a dedicated line for the bov itself because the more vacuum pressure you have for the bov the better it runs, by t'ing that line for the boost guage too you take away vacuum for the bov

not sure how to run a full dedicated line tho. wouldn't it have to tap in somewhere?
 
yeah but by dedicated line i mean tap into a line but run the bov only, im not that familiar with ms3's so if i were you i would ask around on the ms3 thread about possible lines to tap, i know with the msp most people tap into the brake booster line
 
could someone explain the test to see if your bpv is leaking a little more clearly/detailed? i want to check, thanks
 
^ha ha i know you do i was asking that other guy on here who wanted to know how to check if he had a vac/boost leak
 

New Threads and Articles

Back