I was driving last month on a 4hr trip. Did a hard pull passing a guy. Suddenly boost dropped and I got oscillation. If I keep it floored I can slowly peak at 9-10psi. Fast forward 1 month. I have.....
(1) Smoke test, no leak found.
(2) Removed IC, hoses, etc. Nothing wrong. Reinstalled everything and pressure tested as much as possible. Can't find a leak.
(3) I put new silicone hoses about 2 years ago and can't find any vacuum leaks.
(4) Pulled wastegate hoses off of boost solenoids and connected a mityvac to each one. Both rods draw in as they should. Also put a T to both wastegates, connected to a long hose through my window, drove with mityvac pulling 20inches in them, no change. Replaced both boost solenoids with no change.
(5) I plugged the end of my charge pipe and pressurized the CP and my intake with no leaks found. So my intake manifold gaskets and BOV valve are good. No leaks and BOV didn't leak.
(6) Ran a boroscope down into my intake tubes so I could see the turbo inlet blades were perfect, not scraping, both were spinning and continue to spin for a couple seconds after engine was shut off. So they are not jammed or have a dragging bearing, etc.
I am so stumped. This problem happened instantly while driving. It felt just like an IC hose that was loose, a split hose, etc. I had just replaced the short hose connecting my aluminum outlet halves in the middle. I thought it was that again but nope. I also was getting an occasional outlet Vanos error so I during troubleshooting this problem, I pulled the valve cover to put new teflon cam seals, replace cam phaser and vanos solenoid. So anything else that may be loose like one of my catch can hoses, etc. has been disconnected and reconnected. Finally my fuel high and low pressures are normal. I also get ZERO error codes. No 30FF, or anything. JB4 display on my phone shows that it is targeting say 18psi and boost is at 4,5,6psi etc. The only thing I have not seen in person is the actual wastgate flap inside the turbo. Removing my downpipes is very tight and I would probably have to drop subframe a little. I guess I could unbolt exhaust pipes from the downpipe and boroscope in. Even that is a pain because my aftermarket upper exhaust bolts are hard to reach unless I lower the whole rear part of the exhaust.
(1) Smoke test, no leak found.
(2) Removed IC, hoses, etc. Nothing wrong. Reinstalled everything and pressure tested as much as possible. Can't find a leak.
(3) I put new silicone hoses about 2 years ago and can't find any vacuum leaks.
(4) Pulled wastegate hoses off of boost solenoids and connected a mityvac to each one. Both rods draw in as they should. Also put a T to both wastegates, connected to a long hose through my window, drove with mityvac pulling 20inches in them, no change. Replaced both boost solenoids with no change.
(5) I plugged the end of my charge pipe and pressurized the CP and my intake with no leaks found. So my intake manifold gaskets and BOV valve are good. No leaks and BOV didn't leak.
(6) Ran a boroscope down into my intake tubes so I could see the turbo inlet blades were perfect, not scraping, both were spinning and continue to spin for a couple seconds after engine was shut off. So they are not jammed or have a dragging bearing, etc.
I am so stumped. This problem happened instantly while driving. It felt just like an IC hose that was loose, a split hose, etc. I had just replaced the short hose connecting my aluminum outlet halves in the middle. I thought it was that again but nope. I also was getting an occasional outlet Vanos error so I during troubleshooting this problem, I pulled the valve cover to put new teflon cam seals, replace cam phaser and vanos solenoid. So anything else that may be loose like one of my catch can hoses, etc. has been disconnected and reconnected. Finally my fuel high and low pressures are normal. I also get ZERO error codes. No 30FF, or anything. JB4 display on my phone shows that it is targeting say 18psi and boost is at 4,5,6psi etc. The only thing I have not seen in person is the actual wastgate flap inside the turbo. Removing my downpipes is very tight and I would probably have to drop subframe a little. I guess I could unbolt exhaust pipes from the downpipe and boroscope in. Even that is a pain because my aftermarket upper exhaust bolts are hard to reach unless I lower the whole rear part of the exhaust.
