Intermittent 30ff

PaulM

New Member
Jun 27, 2023
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Hey guys,

long time lurker, first time poster here. I have a 07 with 19Ts tuned by Doc Vu. Everything has been great for about a year and a half, but I am running into a super weird issue now where intermittently I will lose majority/all boost. The tune targets at most 20psi, and I easily hit that mark, usually even peaking a little bit over, but now that it's gotten warmer (and it gets worse the hotter it gets) I lose all boost.
What I've noticed:
  1. Happens more frequently the warmer it is
  2. Happens while accelerating
  3. The WGDC on the logs doesn't change
  4. The audible blow off gets quiet (I have an HKS BOV)
  5. The car builds at most 8-10psi after the issue starts.
  6. Restarting the car while driving does NOT solve the issue.
  7. Turning the car off and coming back 30 min later returns everything to normal.
  8. Smoke testing the system shows a small leak near the outlets (however it has been like this since basically the beginning)
  9. No other leaks are found.
  10. Only existing issue on the car is a post cat O2 sensor, that occasionally throws a signal code. (This causes the Cilc to happen quite frequently, perhaps it's better to just disconnect the sensor completely
  11. One time while driving and logging at the same time I glenced at the boost mean and notice it drop from 18 to 3 back to 18. Indicating that maybe something got stuck leaked out and then worked again?
Things I'm suspecting
  1. Boost solenoid (since it is intermittent and it's basically the only electronic part of the whole equation)
  2. BOV sticking/leaking? (not sure how to diagnose this, it doesn't seem to leak in idle, but perhaps under boost?)
  3. I can't imagine it being the actuator arm because it's intermittent and then goes back to working completely fine.
And before you guys say to dump the 19Ts; they have done great for me, but the Speedtech kit is coming soon anyways šŸ˜…