Boost gauge only reading in-hg

[Bfmvloverhxc]

I recently purchased a boost gauge and installed it, I was all sorts of excited to take it for a drive and then when I started my car it was reading around 16 in-hg. I've looked around and some people say it will do that while the car warms up because it needs to build that pressure and then it will go up. But it stays at that until I get on it and then it goes up to 0 but never shows any boost pressure. Any ideas?

 

[Nero Morg]

How did you connect it, to a vacuum line?

 

[Rrusse11]

And/or the wrong type of gauge, it's for a gasser.

 

[Vince Waldon]

And... you have to be pushing the engine against a load to make boost... particularly a waste-gate turbo like the one on your MK2. Accelerating away from a stopsign, a hill, something that makes the turbo work. Once you get the right boost gauge it will be normal to read "0" sitting in the driveway, even if you rev the engine.

 

[Bfmvloverhxc]

Mine is actually a mk4, idk why it says mk2,I will fix that. Even on load thats when it shoot up to 5 or 0 in-hg. I followed the directions that came with the gauge and it said to tap into a vacuum line and came with the t and clamps. Im fairly new to the boost world or tdi world unfortunately

 

[Nero Morg]

Sounds like you got the incorrect gauge. On gasoline engines, you set it up correctly. On diesels, you need to tap it to the intake somewhere. The vacuum system on these cars only runs the brake booster, egr valve turbo actuator, and anti shudder valve. At no point does the vacuum system see boost pressure.

Best place to Install a boost gauge??

Anyone know the best spot in the engine where i should hook up my boost gauge?? Around the intake? turbo? specific place?? i have a 2001 Gold TDI

forums.tdiclub.com

 

[Vince Waldon]

Yup that's the actual issue.. .on TDI diesels the vaccum lines never see intake pressure... only steady vacuum from the camshaft-driven vacuum pump.

You'll have to drill an actual hole in the intake tubing somewhere and add a fitting to install a boost gauge.

 

[Nero Morg]

Also, as a suggestion on a gauge to use, or at least what a correct one for a diesel will look like

NewSouth Performance 35 PSI Boost Gauge (Indigo)

A perfect match to the classic Indigo and Red VW interior lighting used in the MkIV, MkV and B5 models. New South Performance gauges are the premier gauges in the VW/Audi marketplace. Known for per...

www.idparts.com

 

[Bfmvloverhxc]

Sounds like you got the incorrect gauge. On gasoline engines, you set it up correctly. On diesels, you need to tap it to the intake somewhere. The vacuum system on these cars only runs the brake booster, egr valve turbo actuator, and anti shudder valve. At no point does the vacuum system see boost pressure.

Best place to Install a boost gauge??

Anyone know the best spot in the engine where i should hook up my boost gauge?? Around the intake? turbo? specific place?? i have a 2001 Gold TDI

forums.tdiclub.com

Thats what I was afraid of, it had me type in my car and everything so I thought I would be good to go, anyway I can remedy this without buying a new gauge?

 

[Rrusse11]

"I can remedy this without buying a new gauge?"

No.

 

[Vince Waldon]

Chances are your gasser gauge shows both vacuum and boost. If so it's usable, just not optimal as a big part of the dial (the vacuum side) is wasted.

If you post a picture or make/model info we should be able to tell for sure.

 

[Nero Morg]

Basically if your gauge goes up to at least 25psi it'll work. But most gassers don't boost that high.

 

[Bfmvloverhxc]

Chances are your gasser gauge shows both vacuum and boost. If so it's usable, just not optimal as a big part of the dial (the vacuum side) is wasted.

If you post a picture or make/model info we should be able to tell for sure.

I am not sure how to post the picture

 

[Bfmvloverhxc]

I am not sure how to post the picture

Black 7 Color 30 PSI Boost/Vacuum Gauge

GlowShift’s Black 7 Color 30 PSI Boost/Vacuum Gauge Is Essential for Anyone Running a Turbo or Supercharger to Monitor Compression and Boost Levels.

www.glowshiftdirect.com

This is the gauge I bought with a pillar mount

 

[Vince Waldon]

That will work... it will just use the boost part of the scale. Stock boost is in the neighbourhood of 15 psi, so it's only going to use about 1/4 of the dial.

If you search a bit here you'll find threads with suggestions on where to drill in the intake ducting. Some do it in the plastic section, others prefer on the aluminum intake manifold itself.

 

[Rrusse11]

Oops, I'll stand corrected. Hook it up correctly and it'll show boost. But as Vince points out, you'll lose a lot of the dial.
Here's what I've got;
https://www.idparts.com/newsouth-performance-psi-boost-gauge-indigo-gau005-p-3744.html
Mounted on the steering column is the perfect spot IMO.

NewSouth Performance Dual ColumnPod (A4)

Gauge mounting solution for the MkIV Jetta, Golf and New Beetle. This gauge pod goes on top of the steering wheel column. Dual gauge pod. Grab two gauges below to outfit this pod. The most common c...

www.idparts.com

Room for an EGT gauge, oil pressure, etc.

 

[Bfmvloverhxc]

That will work... it will just use the boost part of the scale. Stock boost is in the neighbourhood of 15 psi, so it's only going to use about 1/4 of the dial.

If you search a bit here you'll find threads with suggestions on where to drill in the intake ducting. Some do it in the plastic section, others prefer on the aluminum intake manifold itself.

Ok awesome, ill look around, thank you!!

 

[Bfmvloverhxc]

Oops, I'll stand corrected. Hook it up correctly and it'll show boost. But as Vince points out, you'll lose a lot of the dial.
Here's what I've got;
https://www.idparts.com/newsouth-performance-psi-boost-gauge-indigo-gau005-p-3744.html
Mounted on the steering column is the perfect spot IMO.

NewSouth Performance Dual ColumnPod (A4)

Gauge mounting solution for the MkIV Jetta, Golf and New Beetle. This gauge pod goes on top of the steering wheel column. Dual gauge pod. Grab two gauges below to outfit this pod. The most common c...

www.idparts.com

Room for an EGT gauge, oil pressure, etc.

I thought about doing i steering column mount but ended up deciding on the pillar mount

 

[kennyc24601]

Chances are your gasser gauge shows both vacuum and boost. If so it's usable, just not optimal as a big part of the dial (the vacuum side) is wasted.

If you post a picture or make/model info we should be able to tell for sure.

One (probably the only) advantage of a boost/vacuum gauge will be during car shutdown, the vacuum side can be used as visual confirmation that the ASV is working properly IF the line is connected between the ASV and head. Mine usually shows ~ -10 during shutdown.

Serves as a little piece of mind for a runaway shutdown.

 

[MATPOC]

Thats what I was afraid of, it had me type in my car and everything so I thought I would be good to go, anyway I can remedy this without buying a new gauge?

yes, you can use gasser gauge, it will never go below 0, but reads pressure just the same,
just tap in to the upper intercooler pipe with this

90° Threaded Male NoBuzz Connector

1/8 inch threads, perfect for tapping plastic boost hoses. Built-in "NoBuzz" restrictor that limits boost gauge buzz....

www.idparts.com