[brandonsmerry]

I swear it's a new issue with this car every month... As of yesterday, every day I will, at least once, have one drive cycle where the turbo just stops working all together. Acceleration becomes about 1mph per second, until I shut off the car and turn it back on again. CEL just came on today. Climbing a slight incline without slowing down is not possible... anyone else have this issue?

EDIT: Got home to scan, P2261 code. Seems to have appeared in other vehicles within the 1.6t lineup, but not the 22 seltos.

 

[Speedtek22]

Modern turbos use internal wastegates...from the looks of it Kia uses the Borg Warner K03 on the 1.6T...sounds like it is sticking open.
I'm honestly not a fan of the internal wastegate, but modern packaging and space requirements dictates the use of them. It appears you have to replace the entire exhaust manifold with the turbo as it comes as an integrated piece on these...thank goodness for a good warranty.

I miss the good old days with the external wastegate on my UrS6...now that was a turbo setup...The tall round silver part on the left of the valve cover...that's the housing for the wastgate spring. You could dial that baby down a couple turns in the winter for more better boost...lol

 

[brandonsmerry]

Modern turbos use internal wastegates...from the looks of it Kia uses the Borg Warner K03 on the 1.6T...sounds like it is sticking open.
I'm honestly not a fan of the internal wastegate, but modern packaging and space requirements dictates the use of them. It appears you have to replace the entire exhaust manifold with the turbo as it comes as an integrated piece on these...thank goodness for a good warranty.

I miss the good old days with the external wastegate on my UrS6...now that was a turbo setup...The tall round silver part on the left of the valve cover...that's the housing for the wastgate spring. You could dial that baby down a couple turns in the winter for more better boost...lol
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I got an appointment with the dealer and they're looking at it, among other issues with this vehicle that seem to only be an issue on the SX turbo model... I've had Hyundai's for years, 5 to be exact, and I figured how much different in reliability can they really be? Apparently allot lol. The light went off today, and didn't have the same issue, so maybe we will see tomorrow. All I know is that pulling out in traffic to do a left turn and it cut out on me wasn't my favorite memory in a vehicle.

 

[Speedtek22]

I got an appointment with the dealer and they're looking at it, among other issues with this vehicle that seem to only be an issue on the SX turbo model... I've had Hyundai's for years, 5 to be exact, and I figured how much different in reliability can they really be? Apparently allot lol. The light went off today, and didn't have the same issue, so maybe we will see tomorrow. All I know is that pulling out in traffic to do a left turn and it cut out on me wasn't my favorite memory in a vehicle.

Yeah, it wouldn't be...if the wastgate sticks open the turbo goes full bypass and doesn't spool up for boost.
Throw in the inevitable ECU code throws which are probably dialing things down to prevent other problems and it would be a slug for sure.
Interestingly the KIA 1.6T appears to run a fairly high compression for a forced induction motor (10.5:1), I suppose the direct injection helps a lot with pre-ignition potentials.

 

[Xcalibur255]

The 10.5 compression ratio is part of why this engine feels so peaky and inconsistent. If the computer fully advances spark timing this motor pulls hard, even this 175HP version feels very healthy. On the other hand, you get those times where it pulls timing a bunch because it thinks conditions are not optimal and it feels dead like half the power is missing, because half the power actually is missing. Part of me loves the robust low-end torque of turbo engines, but honestly I'm pretty tired of them in general because of the inconsistent performance.

 

[Speedtek22]

Most turbo engines don't really come to life until you hit around 4500-5000 rpm.
Manufacturers can mitigate this somewhat by using variable vane turbos or two stage turbos with a smaller (faster spooling) turbo for initial boost. Both options are fairly pricey and complex and really don't get used other than higher end applications.
I've owned plenty of well tuned turbos over the years and it's amazing how much they wake up with proper aftermarket flash. My MTM stage 1 UrS6 was a beast off the line (Quattro ftw) and once you hit 4k rpm it pulled like a freight train all the way to 220 km/h (fastest i took it before shutting down). I also had a nice VW Turbo S bug that had a stage 1 APR flash in it that was crazy quick...stock it was just..meh.

The problem with stock tunes is they are usually set for driveability and fuel mileage, not performance

 

[Old Car Nut]

The 10.5 compression ratio is part of why this engine feels so peaky and inconsistent. If the computer fully advances spark timing this motor pulls hard, even this 175HP version feels very healthy. On the other hand, you get those times where it pulls timing a bunch because it thinks conditions are not optimal and it feels dead like half the power is missing, because half the power actually is missing. Part of me loves the robust low-end torque of turbo engines, but honestly I'm pretty tired of them in general because of the inconsistent performance.

Actually, I believe the higher compression ratio makes the engine feel less peaky when it is not on boost. Back years ago, turbo engines ran 7:1 to 8:1 compression because the knock management systems were not as effective. Those engines made very little power until the boost came on, and then that sudden increase in power was very difficult for the driver to modulate. Think back to vehicles like the Porsche 930 Turbo and its renowned on/off switch throttle. My experience with early turbos was with a 1989 Ford Probe, which used Mazda's 2.2 liter turbo also used in the MX-6. Trying to put the power down out of a corner was so tough because you had to get on the throttle early and then anticipate when the boost would build, because the sudden surge of power would overwhelm the tires if you were cornering anywhere near the limit.

Higher compression ratios are useful for engines that aren't designed to make a lot of power. Because the static compression ratio is pretty high, it doesn't take much boost to get BMEPs high enough to generate significant torque. And also because you don't or can't use a high volume of boost, turbos can be smaller and spin up faster, without also running out of capacity for airflow. I think it's a pretty good compromise for a vehicle not dedicated to sports-car type operation.

I think that 2.2 liter Mazda motor I had used a 7.8:1 compression ratio. I do remember running it for a day without the turbo as I was exchanging it out for a slightly larger unit. Back then, under about 8 PSI of boost stock, it made 145 HP. I bet that without the turbo, that 2.2 liter made about 80 HP. The car would barely move.

 

[Speedtek22]

Actually, I believe the higher compression ratio makes the engine feel less peaky when it is not on boost. Back years ago, turbo engines ran 7:1 to 8:1 compression because the knock management systems were not as effective. Those engines made very little power until the boost came on, and then that sudden increase in power was very difficult for the driver to modulate. Think back to vehicles like the Porsche 930 Turbo and its renowned on/off switch throttle. My experience with early turbos was with a 1989 Ford Probe, which used Mazda's 2.2 liter turbo also used in the MX-6. Trying to put the power down out of a corner was so tough because you had to get on the throttle early and then anticipate when the boost would build, because the sudden surge of power would overwhelm the tires if you were cornering anywhere near the limit.

Higher compression ratios are useful for engines that aren't designed to make a lot of power. Because the static compression ratio is pretty high, it doesn't take much boost to get BMEPs high enough to generate significant torque. And also because you don't or can't use a high volume of boost, turbos can be smaller and spin up faster, without also running out of capacity for airflow. I think it's a pretty good compromise for a vehicle not dedicated to sports-car type operation.

I think that 2.2 liter Mazda motor I had used a 7.8:1 compression ratio. I do remember running it for a day without the turbo as I was exchanging it out for a slightly larger unit. Back then, under about 8 PSI of boost stock, it made 145 HP. I bet that without the turbo, that 2.2 liter made about 80 HP. The car would barely move.

I find it quite interesting what modern engine management and direct injection can do for turbo engines. Not only are they running a fairly high compression ratio, most info I find on the motor indicates anywhere from 14 to 19 psi peak boost...which is actually pretty impressive on 87 octane especially at those cylinder pressures. (and not punching massive holes in the side of the block)

 

[brandonsmerry]

I swear it's a new issue with this car every month... As of yesterday, every day I will, at least once, have one drive cycle where the turbo just stops working all together. Acceleration becomes about 1mph per second, until I shut off the car and turn it back on again. CEL just came on today. Climbing a slight incline without slowing down is not possible... anyone else have this issue?

EDIT: Got home to scan, P2261 code. Seems to have appeared in other vehicles within the 1.6t lineup, but not the 22 seltos.

UPDATE: A P2261 code in this vehicle apparently means a solenoid valve went bad from sticking open, so good on everyone who knew what they were going to find.

 

[Ktb9671]

UPDATE: A P2261 code in this vehicle apparently means a solenoid valve went bad from sticking open, so good on everyone who knew what they were going to find.

Good luck with your Seltos!! Just took mine in for round 2 after the first P2261 code. That was in March. Each time it loses power and won't let me accelerate when I'm the interstate!! Pretty scary! Hoping this is it, but not optimistic. First Kia and probably the last.

 

[Speedtek22]

It's honestly not even a Kia fault, lots of manufacturers have internal wastegate issues on the turbos installed on their vehicles. The IHI turbos on VW's have an even higher failure rate ime.
One of the reasons I've mostly avoided modern turbo engines and tried to stick with NA versions. Unfortunately to get the options I wanted this round it was either the SX turbo or an EX premium...the EX had a ridiculous wait time for production, so SX it was...