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Decreased performance, boost/wastegate solenoid to blame?

6373 Views 26 Replies 13 Participants Last post by  kampto
2017 with ~25k miles and I was getting on the freeway when it felt like the engine power was cutting in and out. ALmost like boost was fluttering (best way I can describe it). Got out of the throttle and it smoothed out, but immediatly got a CEL. Car was driving fine, so babied it the short drive home. Checked the CEL and it showed P0299 for low boost condition.

Cleared the CEL and went for a drive to see if it would come back. Couldnt recreate the event or the CEL, but the car is noticably slower to respond, seems like it takes much longer to build boost and power. Took it to the dealership to diagnois, and they said it was fine, measure peak boost at ~34psi so doesn't seem to be leaking.

Only had the car for about 8 months so still learning the mechanics, but from what I've learned is that boost/wastegate solenoid (seems like the same part goes by different names?) could be to blame.

Would it be possible that instead of the solenoid not allowing full boost, could it be reacting slowly? So it still allows full boost, as the dealership measured, but just taking twice as long? Also, any tips on how to replace it would be appreciated as well! Thanks!
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Mikesk-Gas is fine, same issue even after adding gas. Interesting to think its retarding the timing, but don't think it would cause a low boost condition?
Excuse me? That should be a big red flag for trusting your dealership right there. Do you have a massive built motor? Stock is what, 15psi normal, 22psi on overboost? I run peak of 28psi, with the average being 24-26psi to redline, and that’s heavily tuned with water/meth.
Well that's definitely interesting. The dealership experience was less than confidence inspiring, to say the least.

From their notes "turbo boost pressure desired highest was 34.9psi and actual was 36.16 psi. Turbocharger is actually working better than the computer is commanding".

I'm still learning about this car and wish I knew what psi was normal for a stock car. I sure would of made a bigger deal out of it than I already did!

So my question is now, is it physically possible for the stock turbo to reach ~35 psi? Is the dealership just full of it?
Or is something else hindering the performance where the ecu is asking for that much boost to compensate to hit the power target?

Actually, thinking about it now, I bet their measurement is absolute pressure and not gauge pressure. Subtract 14.7 psi from their measurements and things look more in line.
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