89 GTE Makes a fog horn noise

[cinderMK3]

I didn't have a ton of time with the car this weekend, but I installed a Bosch BPV and started hearing a almost like the description states a horn sound when the car is transitioning from vacuum to positive pressure. the performance of the car seems unfazed. I figured it was a leak somewhere on a line or the inter-cooler from air just vibrating past a loose spot.
I went through the setup three times replaced all my vacuum lines, and checked all clamps on the tubing, but cannot for the life of me get it to stop.
and its only when I hit 0-2 psi on the gauge ALWAYS, it will not deviate from that. ( That's when I just hold it on that low pressure. If I just boost past it It will not make the sound)

The next step is to put the old BPV back on the car and see if it will do it.

I just wanted to toss this on here and see if anyone has had a similar issue, or maybe there is something silly I'm over looking.

-cheers

 

[akito]

I have experienced this with my Bosch BPV. The car performed well but that sound was soo annoying i switched it out for a Greddy one and it went away immediately.

 

[cinderMK3]

Interesting,
Is it all of them that do this? Ever get a reason on why it does it?


Also is the Greddy one still available?

 

[MichiganLC]

I hear the same noise occasionally with my Bosch BPV.


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[cinderMK3]

Well as long as it isn't doing any damage to anything internally I'll put up with it for the time being.

Just cant stop thinking of that video, of the two cars side by side and the crying Girlfriend on the phone. Hwoooooo

In the mean time I'll Keep the soup out to sea occasionally coming into port.

 

[Nick M]

Interesting,
Is it all of them that do this?

No.

 

[cinderMK3]

No.

When I get an opportunity I'll put the old one back on and see if it goes away.
Nick, If it's happening to multiple people and goes away after the old one is put back on, any idea on the cause?

 

[BlackDevilSupra]

This woot sound has been the case for the Bosch / Porsche BOV since peop's started putting it on the Supras. My recollection dates this mod back to pre-yr2000. What's old is new again
http://supras.com/06/techcenter/display.php?QID=19

 

[cinderMK3]

This woot sound has been the case for the Bosch / Porsche BOV since peop's started putting it on the Supras. My recollection dates this mod back to pre-yr2000. What's old is new again
http://supras.com/06/techcenter/display.php?QID=19

Thanks for the info Black, pretty neat little write up.

 

[Nick M]

Nick, If it's happening to multiple people and goes away after the old one is put back on, any idea on the cause?

I am only answering for mine when asked if all of them do it. That sound file posted from supras.com does not happen with mine, which is an automatic trans. Bypass valves make noise when working. However, that noise is new to me. When air is compressed and released it makes noise.

 

[cinderMK3]

I am only answering for mine when asked if all of them do it. That sound file posted from supras.com does not happen with mine, which is an automatic trans. Bypass valves make noise when working. However, that noise is new to me. When air is compressed and released it makes noise.

It would be something to try and play around with it tho. Maybe in the future when I replace it i'll put a small drop of oil in it to see if it will stop the membrane from what I can only describe as finding its resonance.

Good point tho Nick, I have a Manual Trans myself. If earlier replies read this, what types of transmissions do you have?

 

[MichiganLC]

Auto


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[cinderMK3]

Played around with this a little more. The Bosch is off and the sound is gone.
Nick what turbo you run on your ride? Michigan what's on yours?
I will try to get a chance this weekend to lightly oil the membrane on the Bosch and put it back on and see what it does.

 

[MichiganLC]

57 trim ct26


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[Nick M]

T04E compressor from the old SupraSport. The turbo is no longer sold, the Boss Jr.

 

[akito]

Mine wasn't doing it for the 1st year of ownership then 1 day it started and stayed that way lol

 

[suprarx7nut]

My Bosch BPV makes the "hoot" sound on partial boost. It's annoying. On most Porsche/Audi's with a 3L+ turbo motor, they use two of the Bosch BPVs. I'm not sure if the hoot goes away if you use two BPVs and lessen the volume of air going through each one.

I'll be switching it out at some point, but it doesn't seem to affect the function so it's low on my list. My guess is it would also be eliminated if you used a Bosch style BPV with a different diaphragm material. I think the Bosch is rubber.

 

[cinderMK3]

Ok, I didn't forget about this I went on vacation and have been trying to settle back in. I oiled the Bosch today, I should have oiled then installed but I was missing the car so I drove it around and then oiled the Bosch. I'll save myself the hot finger torture and put it on tomorrow.
I also (not really sure any other ways to word this) Worked the membrane Via my mouth suction, to ensure the Tiny amount of oil I lubed the membrane with would, evenly distribute.
the Valve seemed to lift evenly when viewing inside the BPV.
Before hand it almost looked as if only one side of the membrane was lifting unevenly. Not sure If I'm just shooting in the dark but I'm curious to see if I can shut this thing up.