0.3 psi?????

[IzzyGray]

Just installed a pre owned p3 gauge and finally got it to work(kinda). At idle or stop, gauge is reading between -17 to -22. However at full wot, it's only boosting to 0.3 max. Only weird symptom is a slight whistle(sounds almost like a creak) as I start moving. Could a leak cause normal vacuum reading but low boost? I have a stage 2 AA kit that should show peak 8 psi(give or take)

[tymles]

Sounds like you have a vac/boost leak somewhere. I had the same issue when I installed the same gauge with my ESS kit. Make sure you zip tied every connection point. That solved my problem and you will def feel the difference. Hope that helps. Good luck

[IzzyGray]

Originally Posted by tymles

Sounds like you have a vac/boost leak somewhere. I had the same issue when I installed the same gauge with my ESS kit. Make sure you zip tied every connection point. That solved my problem and you will def feel the difference. Hope that helps. Good luck

Would it read vacuum to -20 if there was a leak though? Generally a leak would keep pressure closer to 0(equilibrium) right? Unless it's a one way leak.... I'll double check connections to be sure.

[HP Man]

Does the car make power? If you actually only have boost of 0.3 psi, then you should immediately notice it. If the car makes normal "boosted" power, then your gauge is broken.

[IzzyGray]

Originally Posted by HP Man

Does the car make power? If you actually only have boost of 0.3 psi, then you should immediately notice it. If the car makes normal "boosted" power, then your gauge is broken.

It's definitely more power than stock but i don't really know how a properly boosted M3 is supposed to feel on the kit that I have. I'm gonna try blowing into it and seeing if it measures more than 0.3 psi.

[SflBimmer8484]

Originally Posted by IzzyGray

It's definitely more power than stock but i don't really know how a properly boosted M3 is supposed to feel on the kit that I have. I'm gonna try blowing into it and seeing if it measures more than 0.3 psi.

Please take a picture of where you have it connected.

[IzzyGray]

Originally Posted by Andrew@ActiveAutowerke

Please take a picture of where you have it connected.

It's T-eed off the main vacuum hose that has branches to the 3 BOVs. You can see it in the above picture(it's the line that has two different sized hoses sleeved over each other)

[IzzyGray]

Slight update: I disconnected the vacuum hose from gauge control box and blew directly into the control box sensor and it's registering at most 2 psi no matter how hard I blow into it. So the sensor is bad?

[tymles]

Yes it would still read the vac. If you blow into the tube and the gauge reading changes, the gauge should be working. I noticed that you didn't zip tie the connection where it was t'd off the bov. When you start hitting higher boost, it seems to leak from those points, at least for me, that was the issue. I simply went back and zip tied EVERY connection point, including where the tube connects to the box under your dash. That fixed the problem. That would be my suggestion as it sounds like the exact symptoms I had.