# VDO Boost Gauge rattle/ vibration?



## Marble (Nov 20, 2002)

Hey what's up here? I did a search and found no info on the mentioned problem that I am having. I had an Autometer boost guage and no probs. I recently purchased and installed (brand new) VDO Vision Boost Gauge with the blue LED to "match" the interior of my car. Well I took it out after the install, and I get a little rattle from inside the gauge when I am building boost







. This goes away when I am heavy on the throttle at after 8 psi on its way to 11. It's hella annoying and thinking about returning the gauge to SUMMIT and try another Vision gauge. I had seen posts about this before but cannot seem to find one under "boost gauge" "boost gauge vibrations/ rattles" so any info would greatly help. Thanks!


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## sveda (Apr 18, 2001)

*Re: VDO Boost Gauge rattle/ vibration? (ATXGTI)*

I had the same problem with a couple of boost gauages on my car. I think the problem is slight pulses in the intake manifold that cause the gauge to flutter. The fix is very easy. Buy a cheap in-line fuel filter that you can splice in-line to the gauge, near the gauge. The volume of air in the fuel filter will smooth out the pulses and stop the gauge from fluttering. If the noise is still there but less, you need a larger filter (more volume) or buy another filter and put them both in-line. I used a $1.99 filter from AutoZone.


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## Kenji (Jul 13, 2001)

*Re: VDO Boost Gauge rattle/ vibration? (ATXGTI)*

The rattle you hear is caused by the needle vibrating against the pin that stops the needle from reading less than 0 PSI. I agree that it's annoying. Your Autometer gauge probably read vacuum as well as boost, so there was no stop pin at 0 PSI, and hence the Autometer gauge didn't have this problem.


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## Marble (Nov 20, 2002)

*Re: VDO Boost Gauge rattle/ vibration? (Kenji)*

*sveda* 
Thanks for the idea with the filter, I still don't understand what the rattle/ vibration noise is though







? Does not seem that the gauge is manufactured well if I have to use a "filter" with it







? Oh well. 
*Kenji* 
The VDO gauge is the Vision series which does read vaccum (sp?), so I don't think that the needle is rattling/ vibrating against a "stop" pin, especially considering that it happens around 3-5 psi, and after 8 it goes away (read original post). 
Thanks


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## sveda (Apr 18, 2001)

*Re: VDO Boost Gauge rattle/ vibration? (ATXGTI)*

Neither of my gauges ever rattled against the stop pin either, they rattled between 2 and 4 psi like yours.
Keep in mind that the manifold pressure WILL change slightly every time one of the intake valves opens, and that you gauge is located at the end of a long thin tube. As pressure waves go up and down the tube they will oscillate and resonate, just like steam and water pipes do.
I don't think the problem is with the gauge. It's the entire system, if the factory mounted a boost gauge they would probably tap into a vacuum line inside the dash that goes to other systems. The volume of air in the other systems inside the car (cruise, HVAC, etc.) would "absorb" or filter the pulses just like the in-line filter does.
I'm an electrical engineer, I am sure a mechanical engineer could give a better explanation.


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## Kenji (Jul 13, 2001)

*Re: VDO Boost Gauge rattle/ vibration? (sveda)*

I just drove my car to work. You guys are right. The buzz is just the needle vibrating, not the needle vibrating against the stop pin.


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## fatmobile (Nov 11, 2002)

I heard a restrictor in the line, close to the gauge, will reduce the vibration,
without adding a large volume that could slow the gauge movements too much.

I can't remember the size of restrictor,
a small adjustable valve might work, allow you to tune it.


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## VDub Dan-O (Mar 24, 2010)

Do a Google search on boost gauge buzz for ideas and pictures.

I ended up taking JB weld and filling in the Vacuum tee portion that goes to the gauge.
When the stuff set up, I drilled a .040" hole in the JB weld and no more buzz.


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## BLSport (Dec 24, 2005)

I had the same issue when I installed my first boost gauge years ago... I slipped a 22-18 AWG insulated crimp butt splice into the line (hose in my case; was a nice snug fit) that feeds the boost gauge, and it worked like a charm... just enough of a restriction; gauge is very responsive, no more needle flutter.


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