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Discussion Starter · #1 ·
Hi All,

Wanted to post this to help anyone who may be having the same issue.

About 2 1/2 years ago, I started having a loss of boost at 3,000 rpm with a cold engine under hard acceleration (2016 FORTE5 SX Technology). At first the dealership could not find anything wrong but finally, 7 months after the issue started, the vehicle threw a check engine lamp. The code came back as P2261 (Boost Pressure Control Valve). The dealership put in a new RCV which solved the problem, for about 2 months and then it returned. Once again, they could find nothing wrong. Needless to say, I was not pleased but I took my car back. The problem continued to get worse and they finally started throwing parts at it. over the past 2 years I have had every part of the turbo system, including the turbo, replaced except for the Intercooler. On the last visit, they replaced the low pressure fuel line, the rcv valve, the rcv solenoid, the rcv valve again (3rd time) and the purge solenoid before returning my vehicle back to me with the same problem. At that time, they decided to tell me that it was normal operation of the pcm limiting the boost to protect the engine when cold. Knowing that this was just them trying to make a problem go away because the problem wasn't there when the vehicle was new, I nonetheless took my vehicle back and decided that I would just wait until something failed completely.

They had actually returned my vehicle back to me outside of warranty after putting 298 miles on it. That repair lasted from March 16th until April 19th of this year.

So, I've been driving my vehicle since then and the problem has continued to get worse. It has now started happening with a hot engine and throwing check engine lights every few days.

I finally had enough and opened a case with Kia Consumer Affaisr and returned my vehicle to the dealership last Friday. I decided to wait and actually work with the tech (I used to work at this dealership which made this even more frustrating). While the tech was looking at live data on KDS, I drove my vehicle in numerous different fashions. The tech who looked at the vehicle this time noticed that under wide open throttle, The boost numbers were perfect. However, under just normal driving, the vehicle was producing 10psi more boost than was desired and had an active P2261 which went to history when the vehicle was turned off. We pulled back into the dealer and he started taking things apart. We couldn't believe it was the RCV as that had been replaced 3 times already but the code was leading us to that again.

Well, after inspecting all of the hoses for a vacuum leak, we decided to remove the RCV again. Low and Behold, after less than 2 1/2 hours, we actually found the problem. The problem should have been discovered years ago but they failed to do one thing. Each time the RCV was replaced, they failed to remove the spacer that goes between the RCV and the Intercooler. Had this happened, the problem would have been apparent instantly. There was an air leak between the spacer and the Intercooler caused by corrosion. The reason the first RCV fixed the problem for a while was because when it was replaced, they torqued the new RCV down which sealed the leak for a short time. As the corrosion built up, the leak became worse which, in turn, caused the problem to get worse over time. The vehicle will be getting another RCV, a new spacer and a new Intercooler tomorrow.

This process has been infuriating and I am hoping to spare someone else the frustration I have had for the past 2 1/2 years. If you are getting a loss of boost, make sure the dealer looks under that spacer for corrosion and does not just throw a RCV at the car.
 

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Finally good troubleshooting.
Small part, cheap fix... but a tiny detail makes the whole picture messed up.

However, yes indeed, the boost is limited on cold engine. Until the coolant reaches 60 deg C, boost will be heavily limited, even down to 5 psi boost when you are at 0 deg C.
I experienced that with two models: 2015 MT and 2016 AT - both F5 SX.

Thanks for sharing.


So it would just drop boost, or it would be limited?
I guess on cold it was leaking more than on hot - metal expansion?
 

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WOW great info thank you very much for sharing this with the forum.
Hope all is well now and you can enjoy your ride.
Thanks again :)
 

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Discussion Starter · #5 ·
PLP,

It was dropping boost for an instant at 3,000rpm. It felt like a momentary misfire but when viewing live graph data, you could see the boost pressure drop for just a second. Also, yes it was leaking more on a cold engine than hot until the corrosion built up so much that the metal expansion could no longer limit the leak.
 

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Discussion Starter · #6 ·
lephoenix,

Part Number - 282332B710 (Adaptor)

Price - $29.67

There is also an o-ring that fits into the bottom of the adaptor. I could not find the partt number or price of that but once I have my invoice back I will post that info. The dealership is also replacing the intercooler due to pitting of the aluminum from the corrosion.
 

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lephoenix,

Part Number - 282332B710 (Adaptor)

Price - $29.67

There is also an o-ring that fits into the bottom of the adaptor. I could not find the partt number or price of that but once I have my invoice back I will post that info. The dealership is also replacing the intercooler due to pitting of the aluminum from the corrosion.
Thanks! Might be something worth taking a peak at and replacing as these cars get older.
 

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Discussion Starter · #8 ·
UPDATE:

Sadly, this did not fix my problem. The vehicle now has more power than before but the code returns as active when the vehicle is being driven and moves to a history code once the vehicle is turned off. KIA, in their infinite wisdom, has finally, after over 2 years of me asking, decided to send an FTS to diagnose and fix my car. No ETA on when he will arrive but I will keep you all posted on the progress.
 

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UPDATE:

Sadly, this did not fix my problem. The vehicle now has more power than before but the code returns as active when the vehicle is being driven and moves to a history code once the vehicle is turned off. KIA, in their infinite wisdom, has finally, after over 2 years of me asking, decided to send an FTS to diagnose and fix my car. No ETA on when he will arrive but I will keep you all posted on the progress.
Did you ever get it fixed?
 
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