2018 Stinger cylinder misfiring

[Stinger89]

In need of some advice. A little over a week ago my 2018 GT2 Stinger began jerking hard, and then shaking. The engine light came on and it felt like I was starting to lose power, so I was able to pull over safely and have it towed to my local Kia dealership. They had my car for a week, told me that 3 of my engine cylinders were misfiring a few days after they had it. Today I was told they were finished with it, and it was ready to be picked up. When I picked it up, they told me that when they test drove it they had no issues, and that no codes were showing up "active", and the next time my check engine light comes on I am to drive it straight to the dealership so that they can see the active codes. Needless to say, I am furious that they kept my car for a week and did nothing, and now I need to wait for my car to break down on me again, and magically be able to make it to the dealership before anything is fixed. I am attaching the codes they were able to see as pending to this post. Any thoughts?

 

[Luc343]

There is a log in the ecu for all the faults that have occured to your engine. They have a tool that plugs into the obd2 port to read all the faults. The fault codes remain until someone manually clears them.

They have no excuse for not seeing the fault codes.

 

[Stinger89]

I attached a picture of the fault codes that they saw. They said that because there was no issue during the test drive, and none of the codes were "active" at the time it was in the shop that Kia did not want to look into it any further and they were told to "release it back to the owner".

BTW I only have the fault code list because I emailed the Service Advisor demanding them for my records. In his email back with these pictures he said "hopefully it may help and you can resolve the issue", AKA good luck, I hope you get it figured out on your own.

 

[MerlintheMad]

Howdy and welcome to the forum. Hope you get to sort this out instead of having uncertainty hanging over you.

 

[stoopid]

My last car (NA V6) I had a cylinder misfire suddenly on the highway, was in limp mode the moment I got off the highway after the first stop light. Pulled off, cleared the code, and it never returned. Unrelated, a couple weeks later I traded it in for the Stinger, but ran fine for those few weeks.

Misfires can be bad gas and/or moisture, etc. The fact they're alternating cylinders would tell me they're on the same side of the engine(?). Wonder what could trigger misfires on one side and not the other, bad gas/moisture would likely affect all cylinders, or random ones. Is there any chance the air intake is compromised? If the air fuel mix is wrong or the air flow sensor is reporting incorrectly, it would certainly cause the engine to calibrate incorrectly.

Just throwing some ideas out there.

It may be nothing though, if you clear the codes and they don't return I wouldn't worry much about it. How many miles? Any tuning/aftermarket parts?

 

[oddball]

Yeah, it was all the cylinders on one bank. That would imply to me some sort of intermittent wiring problem, like a loose bundle of wires going to that side of the engine.
That kind of problem is extremely hard to diagnose, so no surprises there. A week is pretty long, but the result is normal. This is just the way it goes with intermittent problems.

 

[Nando_Stinger]

I'm having the same issue as you are on a 2022 gt2. I'm having misfires on cylinders 2,4,6. Been trying to get the dealership to fix buts it's been difficult since the codes clear when the car is turned off then turned back on...

Did you ever get any resolution on your issue?

 

[BuddhamanJB]

Having the same issue on my 2019 GT, any resolution to this? I've already changed plugs and coil packs.

 

[Nando_Stinger]

I have taken my stinger to the dealer with this issue twice so far. First time, they didn't do much and said they didn't find anything, reset the ECU and gave it back to me.
This second time, they are actually now in contact with Kia engineering and are trying to figure out what's causing the misfiring.
So far , they have told me that they checked spark plugs, coil packs and injectors and that everything looked good so far. They are going to clean a ground wire in one of the harnesses, reset the ECU and see if that helps. It's still at the dealership but once I get it back I'll post an update on what they tried to fix this issue.

 

[BuddhamanJB]

Thank you for your reply. I'll be taking mine in next week. Do you have any mods on yours? I did an MRBP cat-back exhaust, K&N short ram intakes, and HKS SSQV blow off valves.

I thought the blow off valves could be causing the issue from some things I've read online about using them without having the car tuned, but alas it happened anyways. Now it's in my head that it could be the K&N intakes. But that could just be me going nuts over this issue lol.

 

[Nando_Stinger]

No mods.
I've been told about the potential of bad gas too but I made sure to buy only Chevron and only premium but it still misfired several times.
The problem is that when the car is turned off and then back on, the code clears and if you drive it enough, the stored codes clear you can only read with an obd reader clear too. The dealer told me that Its ok to bring in the car without the CEL on but it needs to have codes stored from a previous CEL event(light off, codes stored in ECU). But if there's no CEL and no stored codes, there's nothing for them to diagnose.

 

[BuddhamanJB]

Every time it's happened to me, I plug in my reader and all of the codes are pending. I normally clear the codes, but today I didn't, After about 25 miles of driving, the CEL came on again and I got a message on my radio that there is possible engine system failure and to schedule service. What's also odd is that every other time it's happened the car goes into limp mode, but this time it didn't. When I plugged my reader in again, the codes had gone from pending to stored.

 

[Nando_Stinger]

I think what my stinger does is also go into limp mode but I'm not sure. Should you expect loss of power when misfiring?
One time, I allowed the car to idle with the engine shaking(I think in limp mode or misfiring or both) and I looked at the misfire counts through the obd scanner and they were increasing just simply parked with the engine idling(CEL on, engine shaking; huge loss of power when accelerating from 0mph).
I've never had my codes stored only pending.

 

[BuddhamanJB]

When it first happened and went into limp mode it scared the crap out of me. I didn't know what limp mode was. Massive loss of power, no boost. I thought the car was screwed. I later read that these newer cars do go into limp mode from misfires.

 

[BuddhamanJB]

I have taken my stinger to the dealer with this issue twice so far. First time, they didn't do much and said they didn't find anything, reset the ECU and gave it back to me.
This second time, they are actually now in contact with Kia engineering and are trying to figure out what's causing the misfiring.
So far , they have told me that they checked spark plugs, coil packs and injectors and that everything looked good so far. They are going to clean a ground wire in one of the harnesses, reset the ECU and see if that helps. It's still at the dealership but once I get it back I'll post an update on what they tried to fix this issue.

Just curious if they were able to find and fix your issue?

 

[Nando_Stinger]

Just curious if they were able to find and fix your issue?

Still at the dealership. I will reply once I get my stinger back.

 

[BuddhamanJB]

Still at the dealership. I will reply once I get my stinger back.

Hey man, not sure if you've had any luck, but maybe my experience will help you. I took my Stinger in a couple weeks ago and they said I had the incorrect spark plugs and gap. I told them it was happening prior to the plugs being changed, but they said there are lots of issues with aftermarket plugs in this motor. I sucked it up and had them change the plugs.
The next day I got two misfires and car went into limp mode again. I brought the car back last Thursday and they've had it ever since. They had two master Kia technicians looking at it and they could not figure it out. The had a KIA engineer come in on Saturday and Monday and after running a bunch of tests they said the issue is that the High Pressure Fuel Pump is leaking. They are going to change that free of charge to me since they misdiagnosed the first time. I should be getting the car back today. I'll let you know if the misfire happens again. They sound pretty confident that this is issue, but I'm not getting my hopes up yet.

 

[Nando_Stinger]

Hey,
They still have the car. I was told that they have a service line/call between them, the dealership, and Kia engineering. It sounds like the dealership techs are going back and forth with Kia engineering to try to resolve the issue so they are often times just waiting for a response from Kia engineering. Still no updates. My car hasn't been turned in in two weeks. I get notifications whenever it does get opened or turned on.

Thanks for your update though. I'll mention it to the techs the next time I talk with the dealership.

I will update here once I get a response.

 

[Nando_Stinger]

So I just talked with the dealership today and they said that I'm getting my car tomorrow.
They fixed the misfiring issue and did the recall work too. They didn't have to pull the engine for the recall work.
Apparently, the part that was causing the misfiring was a solenoid. Don't have anymore details other than that. I'll review the documents once I pick it up tomorrow. I'll ask for the part number too and I'll actually be asking for the defective/broken part.

I really hope this fixes it.

 

[BuddhamanJB]

Interesting. Keep me posted if it happens again. I'll let you know as well. My Fuel pump is on backorder so who the hell knows when I'm going to get me car back
Good luck I hope it's fixed!