Ok I have a Prosport boost gauge tapped into the line on the IM as listed on VFAQ and when im at full boost (15psi) I can hear a hissing from it (for some reason I only seem to hear it in 1-3rd. Could be thats what im usually in tho, so I havent noticed it yet). Its holding right at 15psi fine, a little spike up top. But no biggie. But that hissing is making me wonder if im loosing boost through it?? I re-attaced the hose, REALLY crammed that F'er on this time. I nice tight zip tie. But still the same noise. Now im thinking "Is it an internal leak?" Little confused on how I would leak test a boost gauge without tearing it open. And that id really rather not do. But id definatedly sounds like its coming from the gauge. Is it possible that the air just rushing through their is making it do this? This just started after fixed boost leaks and raised the psi up from 12 to 15.
Boost Gauge Leak??
speedin
1 - 15 of 15 Posts
Ok I have a Prosport boost gauge tapped into the line on the IM as listed on VFAQ and when im at full boost (15psi) I can hear a hissing from it (for some reason I only seem to hear it in 1-3rd. Could be thats what im usually in tho, so I havent noticed it yet). Its holding right at 15psi fine, a little spike up top. But no biggie. But that hissing is making me wonder if im loosing boost through it?? I re-attaced the hose, REALLY crammed that F'er on this time. I nice tight zip tie. But still the same noise. Now im thinking "Is it an internal leak?" Little confused on how I would leak test a boost gauge without tearing it open. And that id really rather not do. But id definatedly sounds like its coming from the gauge. Is it possible that the air just rushing through their is making it do this? This just started after fixed boost leaks and raised the psi up from 12 to 15.
Joined
·
1,008 Posts
You hear it on the inside like where you actual gauge is? I think mine is leaking too then, it does it all gears, good hiss huh?
Joined
·
20,857 Posts
I have the same thing. I've replaced the gauge but still makes the sound. I've always wondered if it's from an intake gasket leak and it's just being amplified through the tubing. Kind of like the string/cup thing.
Anyone who's had their boost gauge make noise, please post up on what you found and how you resolved it.
Anyone who's had their boost gauge make noise, please post up on what you found and how you resolved it.
Yea it does. Just dont get on the top gears enough to have heard it their yet.dsmersam661 said:
Hum, hope its not the IM gasket. Well my last leak test I can tell you that the upper portion of where the manifold connects is not leaking. So chances are the IM gasket isnt leaking on mine.Red1991TSI said:
I thought, their might be a reducer inside the gauge somewhere and when you pass enough air past, one those can hiss. Really if someone had an exploded view of how the boost gauges work that'll help. It could just be how the air pressure is transfered to the needle making it hiss. Like its hitting something inside??
Joined
·
194 Posts
nice theory , technically the hose would have to be pulled tight. I had the same problem on a 2g. I simply took the gauge off, ran the car with the gauge in my hand, and checked to see where the leak was coming from. It turned out to be the the little crush sleeve that looks like a fishing weight. Bought a new one from autozone and replaced it. it could also be a kink in the hose somewhere.Red1991TSI said:
To bad mine wont come out very far. Id have to have my left hand all the way up in the corner. Ill have to try that tho. And a kink is very possible too.......WAIT! I got an idea. Itll work just like a boost leak tester. Hum imma go fab it up and ill take pix for yafirDehaSwkM said:
Joined
·
205 Posts
Mine leaked and read a false reading until i fixed it all i did was tighten it some more with a new boost wire end.
Joined
·
194 Posts
that is a good idea. pressurize your system to about 18-20psi and you should be able to hear your leakspeedin said:
Ok, just got done. Took some pix (crappy camara-phone ones but you get the point of it). Came to the conclusion I expected. The gauge doenst leak at all. I seperated the line right where I tee'd in so it was just line and guage. Im now thinking the sound is just normal. Well here was my process if you want to repeat my test.firDehaSwkM said:
Here is the parts I used. A air blower , a stepper chuck, some zip-ties, dikes, Soap/Water mix, and a regualted air compressor. The regulator is REAL important. You dont want to much PSI in that line. Bike pump would work too. But G/L finding this chuck for a bike pump.
First you spray the Soap/Water mix ALL over the connections. Basically anything in the system that sees pressure.
Air Blower and Stepper Chuck:
Stepper Chuck up close:
Compressor with regulator set at 25 psi (angles off, but thats 25):
Attaching boost guage line to the fitting (nice and tight):
Zip Tie the trigger down to have constant pressure (not neccesary):
First test I saw the PSI dropping slowly but heard nothing and their were no bubbles in the soap mix on the back of the gauge/line. Then I learned a little something, soak ALL the parts in soap.
So after tightening that down. I held 25psi fine and no leaks.
Joined
·
1,008 Posts
I believe that my plastic line to Boost gauge is kinked then, maybe cracked, cause wheni tried to cut it when i got the gauge, it just bent it up and made it crack, so i kinda looped it under the dash. I got a few questions i hope you guys dont mind, but is that plastic vaccum line junk? Should i run the rubber vaccum line? That tool that was made, will it have enough pressure to fill all the vaccum lines up to find all leaks? if i tap into the bov line?
Thanks this is a really helpful thread because i thought that the hiss noise was normal.
sam
Thanks this is a really helpful thread because i thought that the hiss noise was normal.
sam
Joined
·
20,857 Posts
Actually when I think about this, no they wouldn't. A string would need to be pulled tight but a tube will convey sound regardless. Same theory they use in old submarines. Second example, using a vacuum tube to listen for leaks or noises. Doesn't need to be pulled tight, just not kinked shut.firDehaSwkM said:
Joined
·
866 Posts
I was wondering what brand of boost gauge you guys have? If your all running the same guage it could be a design flaw. I'm running an autometer which runs a hard plastic line that feeds into a threaded housing on the back with a pressure fitting and nut over it. I haven't had any leaking issues. I like the idea for the tester. It could also be used to make sure the guage is reading accurately.
Joined
·
20,857 Posts
I'm running Autometer too. My first was defective. The needle would stick along the sweep at like 7lbs then finally jump to 15. Took it off and verified there was something mechanical inside causing it to hang.
Both have "leaked". I still think I have an intake leak that's amplified within the tubing. I've redone my connection at the gauge end twice, so I'm pretty sure it not that.
Both have "leaked". I still think I have an intake leak that's amplified within the tubing. I've redone my connection at the gauge end twice, so I'm pretty sure it not that.
I am running a "Prosport" gauge. It uses the silicone tubing. Im going to take apart the housing to look for a kink. Only problem is their is a section of tubing I cant see. Its inside the dash 
. Test found no leaks though, nor did it hiss.
Using the noise through the tube idea I came up with another solution. What if the plastic T in the line is creating the noise. Think about it, as the air travels in its normal direction it comes to a hole it can now travel down. This rapid change could cause the noise. And that noise would travel down the tubing easly.
. Test found no leaks though, nor did it hiss. Using the noise through the tube idea I came up with another solution. What if the plastic T in the line is creating the noise. Think about it, as the air travels in its normal direction it comes to a hole it can now travel down. This rapid change could cause the noise. And that noise would travel down the tubing easly.
If your air comressor can take it. It can pressurize any tubing system that you can fit on the one end really. But your vaccum system in full connects to the outside air. So without kinking/sealing off the tubing exits to the outside, you'll just blow air to the outside.dsmersam661 said:
1 - 15 of 15 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
