Built Boost Leak Tester, this is what happens

[McMsk]

Hi Guys,

I have built a boost leak tester , by using a water bottle and an tyre valve from a rim. I put the water bottle into my accodeon hose, and I connected a compressor to it, to put air pressure on the system. Now the strange part: my boost sensor only show 0.05 bar and I hear a tshhh noise from my oil filler cap. When I remove the oil cap, the noise is gone, but it shows no boost at all. Should I retry the thing wihout the underpresure hoses on the accoreon hose, and close the openings? I saw an instruction for an boost leak tester, but it connected directly to the turbo and not to the accordeon hose, but i don't know what he did with the other hoses, which normaly connect to the accordeon hose.

I hope you guys can help me, because I believe I have pressure leak somewhere, as my car stutters under boost, and doesn't build boost properly. Could this also only be because it doesn't get enough fuel?

Thanks a lot

Mark

 

[McMsk]

I now bridged the hoses on the accoredon hose, so the camshaftlid under pressure is not put under pressure at the moment, but for some reason with the throttle valve open i do not reach more than 0.26 bar. How long should the system be able to hold the boost when everything is fine?

 

[SySt]

You pressurized the accordian hose? You are probably leaking lots of pressure through the PCV system. If you are going to pressurize the accordian hose you are best to block off all of the ports on it.

 

[McMsk]

I already did this now. But when I have the rest closed I still cannot pressurize the system more than 0.26 bar with the throttle valve open, otherwise the boost controller only shows 0.04 bar. well that i belive it because the turbo timers boost sensor messures after the throttle valve. but how much pressure should i be able to see with a proper working system? What does the small hose on the bottom side of the accordeon hose do, do i need to block it off as well?

 

[McMsk]

I now also found out, why i was able to boost 1.27 bar without hitting fuel cut also i don't have a fcd. Its because i left my stock bov connected to the accordeon hose to keep the hole shut, but i discovered that it is broken and just let in lots of air, just as if i had a hole in the accordeon hose. Therefore the engine got lots of unmessured air.