BOV Noise from A/c

Post by **Nismo_Freak** » Thu Jul 25, 2002 2:44 pm

Hey my S14 emits a BOV sound (Similar to a Blitz BOV w/Filter) when I give it WOT and shift at high rpms. It only does this when the A/c is on, sound seems to get louder as I turn the A/c up. I think I remember someone else having this occurence? It doesnt do it every time I shift though... it seems like it has to charge up. Ex. Loud noise in 1st with nothing or a small pshh in 2nd then a medium pshh in 3rd. Any Ideas? Im hoping im not fryin my A/c compressor.

Post by **Anand** » Thu Jul 25, 2002 2:44 pm

I get a sound form my s14 as well. But not that many times. I get it when I have my AC on and go from first to second. it does sound like a BOV but i figured it's just how it is. it's been there since i got the car 2 and a half years ago.. so who knows

Post by **AunVoh** » Thu Jul 25, 2002 2:44 pm

i've never had my car do that, does the A/C like cut out or something?

Post by **Nismo_Freak** » Thu Jul 25, 2002 2:44 pm

Its not the a/c cut off since it only happens a slight second after I close the throttle plate aka get off the gas to shift.

Post by **MikeS14240sx** » Thu Jul 25, 2002 2:44 pm

Have you tried checking your vacum hoses. when I was working on my first car (not a 240) and you would pull one of the vacum lines out of the intake manifold and rev the engine it would create a sound similar to the sound your describing when the throttle body closed. Usually if that sound is coming from the car its a vacum leak. Of course I'm not sure if the a/c on a 240 uses vacums. I have a 98 and have never heard a sound like a BOV on my car.

Good luck. sounds like a brain buster:bash

Post by **AkaiRPS13** » Thu Jul 25, 2002 2:44 pm

I have the same on my s13 but its pretty quiet(like hard to hear without the window down and the stereo off and no one in the car making noise on a smooth road in a quiet neiborhood) I was not realy worryed but now i kinda am. can any body put our fears to rest?

Post by **PongAtari** » Thu Jul 25, 2002 2:44 pm

Enjoy it!:ylsuper

Post by **Nismo_Freak** » Thu Jul 25, 2002 2:44 pm

I think I finally peiced together the puzzle. Our A/Cs are designed to shut off under high revs in order to give a bit more umph to pass. When this happens the A/C is still on and will kick the compressor back on when it senses that the engine is no longer under WOT which happens to be as the shift is taking place. Revs slow and the compressor comes back to life but at around 4k RPM which produces a loud audible pshhhh. That is my theory on the matter.

Post by **klorocks** » Thu Jul 25, 2002 2:44 pm

AkaiRPS13 wrote:(like hard to hear without the window down and the stereo off and no one in the car making noise on a smooth road in a quiet neiborhood)

HAHA LMAO

Post by **FrEaK** » Thu Jul 25, 2002 2:44 pm

If it's what i think it is. It's the AC compressor. And those are expensive my friends. :squint

Post by **tex240** » Thu Jul 25, 2002 2:44 pm

that is a very simple fix. the same thing happened to my s14. Your ac belt has gotten loose and needs tightened. If you dont you will fry your belts but is cheap fix even though it sounds cool:icesangel

Post by **neurovish** » Thu Jul 25, 2002 2:44 pm

Nismo_Freak wrote:Hey my S14 emits a BOV sound (Similar to a Blitz BOV w/Filter) when I give it WOT and shift at high rpms. It only does this when the A/c is on, sound seems to get louder as I turn the A/c up. I think I remember someone else having this occurence? It doesnt do it every time I shift though... it seems like it has to charge up. Ex. Loud noise in 1st with nothing or a small pshh in 2nd then a medium pshh in 3rd. Any Ideas? Im hoping im not fryin my A/c compressor.

hehe, yeah...that's me that originally posted about it, seems like it's something common to nissans since a lot of people seemed to have the same thing happening...even torry and his new specV said he's heard his car do it. As far as I know it's harmless

Post by **dorifkin** » Thu Jul 25, 2002 2:44 pm

Many cars have AC's that make a psshhh sound. My '99 sentra does it, my previous integra did it and so on. I believe it happens from very cold air (which has been pressurized) being thrown onto the warm walls of the Air conditioner cavity. I highly doubt it has anything to do with a soon to die compressor or accesory(sp?) belt. Besides the belt should make a squeal sound when the compressor kicks on and off. I hope I helped!;)

Post by **xxtrizz** » Thu Jul 25, 2002 2:44 pm

Im bringin up an old dead thread but it definitly is the fact that your Clutch on your compressor goes in and out. Mine does it on my new system but it is more silent BOV sound at first it freaked me out I thought my muffler was freakin out. But in the end I was feeling the clutch engage and disengage through the accelerator. Not big problem there so I just let it be. City driving it doesnt matter but in higher speeds sounds like a miniature bov.

BOV Noise from A/c

BOV Noise from A/c

intake and exaust

Re: BOV Noise from A/c

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