Spark Plug Issue

[Gviggy]

What plugs and gap you using? Any mods under the hood?

Factory plugs and all stock

 

[dougie]

Maybe something is resting against it or hits into it when the motor is under torque. I hope you get it resolved quickly.

I have a 2018 Stinger GT2 with 16,000 miles. Plug in the # three cylinder cracked 3 months ago and was fixed under warranty. Today the plug in the # five cylinder cracked. Took it to the dealer and the service manager said that the cracked plug problem is endemic with the 3.3l turbo engine and that a fix is ready, pending approval by the EPA. So maybe in a year or two there will be a permanent fix.

 

[dougie]

Cracked the plug in the #3 cylinder 4 months ago - replaced under warranty. Cracked the plug in the #5 cylinder today. The service manager reported that this is endemic on the 3.3L turbos, that KIA has an EMS fix that has been submitted to the EPA for approval, so when the deadhead bureaucrats figure that the change is OK, we may have a permanent fix. Changing plug type/brand is not a fix; the engine pressure is causing the problem. BTW my ride is unchipped.

 

[MerlintheMad]

We had similar symptoms, replacing the coil solved the problem.

Make sure to check all the plugs.

Ah, from the ancient beginnings of the forum, a duplicate story to my own. The coil pack/boot (a unit) needs to be replaced each time you have a cracked plug, or else the bad coil pack/boot will destroy the new plug. My issue began with a recommended spark plugs change, cylinder six had a bad coil pack/boot, but we did not know this: c. two weeks after the new plugs were in, I started getting exactly the same symptoms as the OP: normal driving (not engaging boost) would feel normal: turbos ON and my engine acted like it had a "cold", it stuttered, and finally after c. 4K miles of this the CEL started to come on. The new plug in cylinder six worked fine for c. two weeks, again, then back to the stutter: third spark plug change included the coil pack/boot being replaced: this was the end of March, and so far everything is working fine (until the next time ...).

 

[XGC75]

Add myself to the list. '21 G70 3.3l AWD with Lozic ECU+TCU, 25k miles. Stuttering at high boost in lowish revs, consistent cyl3 misfire. Sounds like I need to buy a new coil pack

 

[Snicklefritz]

looks like you'll need six coil packs since all six plugs look toasted. pay to play they won't cover under warranty unless your their special friend. in any case 60,000 miles is the cutoff for warranty on electrical parts. the next time I need any of this plugs and coils stuff it will be on me and I won't take my stinger to the dealer but instead will go to our family mechanic for new coils and plugs.

Add myself to the list. '21 G70 3.3l AWD with Lozic ECU+TCU, 25k miles. Stuttering at high boost in lowish revs, consistent cyl3 misfire. Sounds like I need to buy a new coil pack

 

[XGC75]

That job is a PITA too. Before I found this thread I thought the plug in cyl3 was simply not torqued down because of how hard it is to get at without removing the intake manifold.

I will say, with the new plugs the car runs fantastic. Plugs were toasty for a while it seems.

 

[desmorider804]

That job is a PITA too. Before I found this thread I thought the plug in cyl3 was simply not torqued down because of how hard it is to get at without removing the intake manifold.

I will say, with the new plugs the car runs fantastic. Plugs were toasty for a while it seems.

Did the plugs solve your issue, or did you do coil packs also?

 

[XGC75]

Did the plugs solve your issue, or did you do coil packs also?

Just the plugs in my case. I haven't touched the coils yet (probably won't)