2011 Kia Optima
So if your like me and would rather die fixing your car than taking it back to the dealer, only to have them fail at another simple task. Then here is the fix for the turbo charger "loss of power/ restart the car everything is fine" problem everyone is bringing in their car for. I started experiencing the problem around 9,000 miles and read over the entire TSB about how they adjust the wastegate to 4.2V to make it shut sooner. But I dont have a OBD scanner or software to read the voltage on the waste gate. I do however have 10 years electronics troubleshooting experience and knew that it was reading a feedback position voltage that was coming from the electronic motor that controls the waste gate. The problem was which wire was it? Well after doing some slick piggybacking on each wire with the connector plugged it I have the answer. If you look at the connector you take off of the motor it is the yellow wire on the connector. If you piggyback off that wire while the connector is plugged in and the car is on (engine not started but radio and everything on)you will see a voltage of around 4-4.7 VDC using the battery ground as ground. As you move the waste gate rod by hand to the left (passenger side) you'll see it decrease toward 0VDC. What you want to do is pull it all the way to the right (driver side) and read the voltage. mine was actually at 4.6 VDC! So if its above 4.3 VDC you have to shorten the rod. Take the bolt off the top of the rear cover on the turbo to make room so you can move it as you need. Take the clip off of the turbo charger side (BE CAREFUL NOT TO LOSE IT!) it is a C clip with a small loop u can hook something around to pull it up and off. And there is a small washer on the other side of rod so take care not to lose that too when you take the rod off. The motor actuator side is a small locknut that i believe is 10mm. you take that nut off and the whole bar should come right off. Loosen a locknut on whichever side shows the most threads and turn it clockwise if its above 4.3VDC (making the bar shorter) and counter clockwise if its below 4.1VDC(making the bar longer). Then make a turn or two adjustment and without locking the nuts down yet put the bar back on the wastegate connection and motor connection and once again push the rod by hand all the way to the right (driver side) repeat this process until your meter reads 4.2VDC (+/- .1VDC) with you pushing the electronic wastegate actuator all the way to the right. once you achieve this lock down the locknuts on the rod and reinstall the rod reverse of removal (IMPORTANT TIP!!!!! tie a small piece of string around the small loop on the C clip when you go to put it back on as if you drop it you will spend 2 hrs like i did looking for it in your engine!!!!!) I hope this helps. I just did it to my car and shes a COMPLETELY different beast as if your voltage was over 4.3VDC it wasnt putting as much closing force on the wastegate as it should, letting exhaust gas slide on by. I would like to take it back to the dealership but after they put 5w-20 in my car when EVEN THE CAP says 5w-30 i have less than no faith in them anymore...