alright another problem in my a4, I’m running 14-15psi and it spikes 16-17 once in a while (diode mode). I was fine for a few weeks, but few days ago I was playing with WRX… i know it was stupid … ok … i was running fine and then I hear this BOOM! it sounded like balloon just popped, I wasnt sure what happened, maybe It wasn’t me, but right after BOOM my rpm dropped and my boost dropped from 14psi to 3or4. So I slowed down a little and tried to accelerate again, and I have no power and my boost goes to 10psi for a second then drops to 4, I pooled over closed my mbc all the way and still boost jumps to 10 for a sec and holds only 5psi… before it was spiking 21-22psi.
1st thought was one of my vacuum tubs popped so I started looking for cracks in a tube, but couldn’t see any, so i connected compressor to one of the tubs and nothing … all lines was fine and hold pressure… then I pooled my dv, it seems it perfectly working condition. last thing I did is cleaned my throttle body and realigned it.
So everything seems ok and I took it for a test drive, i was surprised to see 17 psi again, so I was like aright, everything fine, no worries. but yesterday on the way from work I was little hard on my car again and i lost power again, no BOOM sound this time, it still pools kind of ok till I hit 3.5 RPM, and feels like I have 100 ppl in my trunk on higher rpms.


anyone experienced it before? I would hate to spend $$ on new tb if original can be fixed. I will definitely try to clean contacts on throttle body today.
any other thoughts?

 

Probably not the TB. Get your ecu scanned, your might be overboosting/going into limp mode. If you could be more descriptive about "boom" that would help. Did it come from the rear like an exhaust/backfire boom, or from the engine like severe detonation boom?. Get the ecu scanned.

 

diode wouldn’t let me go into limp mode, haven’t scan my ecu but my cel is off. it really sounded like balloon pooped, i was driving around 60 so i have no idea were it came from and i had few cars around me, like i said I’m not even sure sound was from my car.

 

i’ll check my ecu tonight, but I wasn’t thinking about limp mode only because some other code, not over boosting, would at least flashed sel before getting me into limp mode …

 

You dont always get a CEL when in limp mode. I dealt with limp mode issues off and on forovera yearand never had a CEL.