P3 Vent Gauge Boost Reading/Boost Leak

[froop]

Hello,

My car has a P3 Vent Gauge which was already on there when I purchased the car so I don't really have any sort of user manual for it.

I haven't had it plugged in recently as I've been using my Cobb to live monitor AFRs but I've recently started having a boost leak from the intake side of the car which I can hear when I'm in third gear above 3k RPM, or above 14-15psi. I can literally hear the boost escaping.

I have a feeling that it's from where ever the P3 gauge boost line is tapped but I didn't install it. It usually reads at around -20inHg and reads up to 19psi when on boost but when I plugged it back in it's reading around -2.3 at idle to about 0 when on boost. I'm not sure if there's only one setting for boost readings but even if it was reading some other measurement it still doesn't seem right.

Has anyone else had this issue before? Also, where is the boost line tapped? I've taken apart the intake the CP/BoV many times before but I've never actually looked for this line.

[Solo_M_Tech]

IDK if the line for the p3 gauge would cause that much of a leak. Charge pipe is my vote. Make sure it's not cracked and the clip is facing the right direction.

[135]

The p3cars website has install PDFs and videos that could help:
Quick reference and webpage
Installation manual and video
Boost line tap manual and video

Since you have a BOV, as opposed to the standard diverters, your boost line tap may be slightly different but it should still be there tapped into the line - just trace it from, or back into, the cabin. Since you have a RHD, the line will probably be a longer line that loops around the passenger side to the drivers side and in through the firewall.

[froop]

Thanks guys.

I had a quick look in the engine bay the other night after stopping on the side of the road but it was too hot to poke around but from what I could see the CP looked fine. I have an ER CP which uses the C clip.

It's a small leak as I can still hit 15.7psi according to the Cobb max reading but it definitely feels like it falls on it's face after 3k.

Let you guys know if I find anything tonight.

I have a slight feeling I may actually be the BoV as normally my BoV spring is slightly too weak so at idle it actually holds open half way and when I turn off the car it creaks closed. But lately I haven't heard it. I only noticed the boost leak because I finally broke the new twin plate clutch in.

[froop]

I found the culprit. As suspected, it was to do with the BoV/P3 boost tap. At the T where the two connect, the line going from the T to the BoV had fallen off. Just need to reattach and zip tie again. Might stick a washer in the BoV whilst I'm at it.

[BMW86]

Originally Posted by froop

I found the culprit. As suspected, it was to do with the BoV/P3 boost tap. At the T where the two connect, the line going from the T to the BoV had fallen off. Just need to reattach and zip tie again. Might stick a washer in the BoV whilst I'm at it.

I was going to suggest this but you beat me to it. It's happened to me once or twice before. Glad to hear it's sorted.