Loss of power - no boost after high RPM acceleration
I've been lurking around for a while after buying a 2012 Dynamic Premium Coupe 2.0 Si4 last July. Within the last few days I started experiencing strange problem. I searched the forum and did not find anything similar.
Accelerating quickly, at about 6k rpm the engine loses power and appears to be a total loss of boost from the turbo. Car still runs fine otherwise and no warning lights came on in the dashboard. It just behaves as a normally aspirated 2 liter engine in a big car, which is to say, gutless.
The conditions were very similar all 3 times it's happened. Accelerating on a warm, dry day with the A/C on. Once going up a hill, once while passing on the freeway and once while accelerating on an on-ramp to the freeway. Speeds were 50-70 mph. The engine hits about 6k and sudden loss of power.
I can stop, shut off the engine wait 5 seconds, restart and everything goes back to normal which leads me to believe that it's some sort of sensor issue.
So my question for the Evoque gurus out there is, what would cause the car to open the wastegate and dump all the exhaust out the tailpipe instead of into the turbo? Or what else might it be?
I'm planning of having my local dealer check for fault codes next week but was wondering if anyone has experienced anything similar?
05-10-2019 08:46 PM
Originally Posted by Grimalkin
Did your dealer find anything? I'm having a similar issue but mine never goes back to normal.
Do you have an OBDII device that you can hook up and see the waste gate PWM duty cycle?
Basically if the wastgate solenoid signal is not getting to the solenoid, then the full pressure form the exhaust is getting to the wastegate and it will open much earlier. The wastegate solenoid duty cycle should increase to near 100% until sufficient boost is made, then decrease to allow the wastegate to open and prevent the boost from getting too high. So maybe it is as simple as some problem with the wastegate solenoid or something associated with that.
So I did not take it to the dealership because I haven't been able to duplicate the problem. It seems to have magically cured itself which means it will probably be back someday. It only happened once more since I made the original post but the car has been flawless since. If it does happen again, I'm heading straight to the dealership to read the codes and I'll report back with anything found...