About three months ago I installed a set of Isspro gauges, including a boost gauge. All went well and I was very satisfied, except for this boost gauge noise. So I called Rod from Wildcat, who was more than willing to help, and we tried a couple of things. First we tried a needle valve to slow the flow down, no good. Then we replaced the hard plastic hose with a soft clear hose, no help. Finally Rod sent me a new boost gauge all together, and it's still rattling. It only rattles from about 18-30 PSI, and I’ve pulled it out of the A pillar to make sure it was in the gauge. Does any have any other ideas to try?

 

Yes, you need what is called a snubber. It is a small volume with an orifice in it. It is used all the time on pulsating reference lines in the power station. I am sure you could find one on ebay cheap. The smallest ones are 1/4" npt, in and out, so you would have to bush it down to 1/8" for your fittings and that might look a little campy, so just hide it under the hood somewhere.


Zino

 

Needle valve does the same thing as a snubber. Your problem is probably the gauge itself.

 

If it was the gauge itself, then what are the odds of getting 2 that are bad?? I'd try the needle valve 1st cuz its cheaper, then try a snubber.

 

You need a little volume. Thats what will smothe it out more so than the needle. A needle valve only restricts flow when there is flow. A gauge is dead headed, there is no flow, other than the flow to compress the airspace in the bourdon tube during a transient.

 

Here's a part number for a CAT brand guage snubber:75-3795. I've heard it works better than a needle valve. If it works, let me know -- I'd like to thank the guy that recommended it to me.

brandon.

 

or you just may have a bad intake valve. i don't think you should have any pulsation at 18 PSI.

 

I can hear an ever so slight rattling at 18-20 on mine. Radio and air have to be off and the windows have to be up to hear it, but it's there.

 

Have you tried replacing a section of the boost line with rubber hose? I hear that stops engine noise from transmitting up to the gauge.

 

Make sure you don't have any fuel in the line that goes to the gage, the trapped air will quiet it.

 

If he has fuel in his boost line he has more problems then just a rattling guage.


phox

 

My Isspro EV boost 0-30 does the same thing. No issue just pulsation doesn't hurt anything but I could see it as annoying. I think it just let's me know I'm getting good amount of boost without looking at the gauge.

-CM

 

Thanks for all the help guys, I have yet to try the snubber valve, for now I'll just keep the radio turned up.

 

OOps, thought we were talking about a fuel pressure gage. Hey, where is the pressure take off, mine is glass smooth. I have the bolt replacement near number five cylinder.

 

I drilled and tapped the intake horn when I did my install 3 years ago.
Rock solid, no buzz.