Transmission issue maybe? Older 2013 Kia Sorento v4. Daughter says while on highway all of a sudden when she went to accelerate to change lanes, it wouldn't accelerate. She said the speedometer went down from the 65 she was at and she pulled over on side of highway. She's a brand new driver so it scared her.

I get in it and it seems to drive fine until you try to go past 40. It'll rev the RPMs but you have to slowly cruise it along to get to above 50. No CEL or dash lights and no codes. While in park you can rev the engine and it seems normal. It'll even drive around the neighborhood at lower speeds and you wouldn't think anything was wrong at all but once you try to quickly accelerate to cross 40mph, then you notice the RPMs go up though you are barely increasing speed. Taking it to a shop Monday but the all-knowing Google is saying prepare for a transmission issue. Any other possibilities?

Did you check fluid level? Some transmissions no longer have a dipstick, but if it does, check that first.

Could be torque converter, but that would show up in lower gears I would think.

magnumtmp said:

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Did you check fluid level? Some transmissions no longer have a dipstick, but if it does, check that first.

Could be torque converter, but that would show up in lower gears I would think.

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I don't believe it has a dipstick to check the transmission fluid.

Plugs/wires? Had similar in a '97 f150. Changed plugs and wires.

And yours didn't pop the check engine light when it happened to you?

FDXAg said:

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And yours didn't pop the check engine light when it happened to you?

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no don't think so. Just a loss of power.

My first thought would be misfire or lean condition causing loss of power under load.

FDXAg said:

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magnumtmp said:

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Did you check fluid level? Some transmissions no longer have a dipstick, but if it does, check that first.

Could be torque converter, but that would show up in lower gears I would think.

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I don't believe it has a dipstick to check the transmission fluid.

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Get under it. Pull the transmission fill plug... poke a finger inside to check the level. Fill if necessary.

FDXAg said:

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And yours didn't pop the check engine light when it happened to you?

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Usually associated with emissions problems. However... there may be a resident code that hasn't yet illuminated. Have a mechanic check for a transmission code.

I'd probably guess you have a failing coil or something like that

1agswitchin4lanes said:

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I'd probably guess you have a failing coil or something like that

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Shouldn't it be running rough even at idle?

My Tundra lets me know pretty firmly when a coil goes.

I'll attempt to check the transmission fluid today or tomorrow. Car stuff is not my forte. I would love for this to be nothing more than spark plugs, wires or coils. But I just assumed a failing coil or spark plug issues would either cause a check engine light or cause a rough idle or sputtering. I don't notice any of that. I'll be honest I don't know the last time the plugs and wires were changed, much less the ignition coils.

She didn't accidentally put it in Sportmatic manual shifting mode by any chance?

No, I actually thought she may have accidentally hit the shift knob and put it in neutral and didn't know what was happening, but when I got in it and limped it home..... There's definitely another issue at play.

But on that note, would it be a helpful diagnostic note if I attempted to shift it manually? If it doesn't want to accelerate much beyond 40mph, does that indicate a reluctance to get into 3rd? Would manually attempting this make any difference?

FDXAg said:

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But on that note, would it be a helpful diagnostic note if I attempted to shift it manually? If it doesn't want to accelerate much beyond 40mph, does that indicate a reluctance to get into 3rd? Would manually attempting this make any difference?

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There is a chance that there is an electric solenoid out that would be a simple fix, or leak in the valve body. Someone already mentioned you could do more damage by driving it, I agree with that. Might be too late too….

maroon barchetta said:

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1agswitchin4lanes said:

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I'd probably guess you have a failing coil or something like that

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Shouldn't it be running rough even at idle?

My Tundra lets me know pretty firmly when a coil goes.

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Absolutely not. If a coil is failing, they may idle nice enough and when the RPMs are raised is when they start skipping.

An advanced scantool with mode 6 data capacity can see misfires that fall below the threshold for a hard code.

Well I took it to a trusted shop of mine that I've been using for years and unfortunately they said it looks like the transmission is the issue. They didn't seem to think that a drain and refill would make any difference or extend the life at all.

I know it's likely that the transmission fluid was never changed on the vehicle. I'm sure if I press them they would do a drain and refill with new fluid, but since they seem adamant it won't improve things, is there any point on paying just to try?

Frustrating thing for me is I don't think the vehicle showed any signs of the transmission slipping or having any issues until this incident. We were more worried about the engine having a problem since it's a GDI then the transmission going bad. Didn't realize it could be so sudden.