Changing spark plugs

[Rfleed61]

Hello Everyone, I am a long time Stinger owner, but first time poster. I was looking to gather opinions to get an idea when I should change the spark plugs on my 2021 Stinger GT. The mileage on the car is relatively low, given that I purchased the car new in 2020. It just a tick over 40k miles and mostly freeway. I use a high quality premium gas and the car runs great.

Back in the day, I would do all the maintenance work on my cars myself, but I can no longer do for many reasons. The dealership wants $700 to do it as a “recommended” service interval. I’m calling BS, but wanted to get other opinions. Thanks in advance.

 

[Ohiocruiser]

You are calling BS, about what?? Spark plugs are recommended to be replaced every 42k miles. You can probably save 200-300 if you go to independent shop for replacement.

 

[Daniel @ K8 Stinger Store]

Swapping spark plugs is an important part of maintenance. We recommend going with the HKS M45IL plugs (CLICK HERE) they are great for daily driving and solid replacements to the OEM plugs.

 

[Ah GetFd]

Hello Everyone, I am a long time Stinger owner, but first time poster. I was looking to gather opinions to get an idea when I should change the spark plugs on my 2021 Stinger GT. The mileage on the car is relatively low, given that I purchased the car new in 2020. It just a tick over 40k miles and mostly freeway. I use a high quality premium gas and the car runs great.

Back in the day, I would do all the maintenance work on my cars myself, but I can no longer do for many reasons. The dealership wants $700 to do it as a “recommended” service interval. I’m calling BS, but wanted to get other opinions. Thanks in advance.

Well. There is absolutely nothing wrong with a dealer service charge of USD$700.

This is the official Capped Price Dealer Servicing in Australia.

The spark plugs are changed at 70,000kms or 7 years whichever comes first. 70,000kms = 43,500 kms near enough

From the Kia Australia website

.

Stinger	2023	2.0 T-GDI Turbo Petrol	8 Speed Auto	View Cost
Stinger	2023	2.0 T-GDI CK GT-Line Turbo Petrol	8 Speed Auto	View Cost
Stinger	2023	3.3 T-GDI Turbo Petrol	8 Speed Auto	View Cost
Service Interval (whichever occurs first) Price What's Covered 1 Year or 10,000 km $358.00 What's Covered 2 Years or 20,000 km $545.00 What's Covered 3 Years or 30,000 km $495.00 What's Covered 4 Years or 40,000 km $800.00 What's Covered 5 Years or 50,000 km $402.00 What's Covered 6 Years or 60,000 km $740.00 What's Covered 7 Years or 70,000 km $961.00 What's Covered [td] Your Authorised Kia dealer will perform these tasks at the time of this service: Add Genuine Oil System Cleaner Replace Engine Oil with 5W/30 A5 Replace Oil Filter with Genuine Filter Replace Sump Plug Washer with Genuine Washer Add Genuine Fuel Additive Replace Spark Plugs with Genuine Plugs Top up Windscreen Washer fluid with Genuine Windscreen Washer Fluid Inspect Engine Air Filter Inspect Brake Fluid colour and level Inspect Cabin Pollen Filter Inspect Power Steering System Inspect Tyres (Pressure & Tread) Inspect Suspension Ball Joints Inspect Air Conditioner Compressor Inspect Air Conditioner Refrigerant Inspect Intercooler Hoses and Intake Reset Service Indicator on Dash Display Check for Outstanding Service Campaigns and Recalls Connect Kia Diagnostic System (KDS) and check for DTC`s Kia Roadside Assistance Activation Perform Quality Control Road Test

​

[/td]

The charge is AUD$961.00

In USD thats USD$660.00

 

[Alpinesting]

Ok, just change the plugs. and maybe change the coil packs or have them inspected. In my experience with this 2021 Stinger,

they can be an issue. It seems like that you have avoided the coil pack issue we had and that is great!

 

[Snicklefritz]

At c. 45K miles I had my plugs changed on recommendation. And my problem started two weeks after that - light misfire or stutter under turbo acceleration, and it was variable, at times seeming to have gone away. At another c. 4K miles I went in for oil change and mentioned my issue, which had now become CEL whenever I romped on it and the misfire was getting worse. It turned out to be a cracked plug in cylinder 6. But a couple weeks later the misfire was back - another cracked plug. The bad coil pack was destroying each plug I had put in, but not the original plug before the spark plugs change. I have almost doubled my miles since then and everything is working fine. My MO is to wait until something manifests indicating that it's time to change plugs/coils. Ima pretty sure when I do that I will do coil packs as well, since the OE ones will have over 90K miles on them. If I go longer, fine

Here's the arguable thing. A member of the forum, last year, said he had 220K miles on his Stinger, had changed out shocks and struts at 80K and again at 160K miles - as a matter of routine maintenance - but was still on his original plugs!?

 

[Ah GetFd]

At c. 45K miles I had my plugs changed on recommendation. And my problem started two weeks after that - light misfire or stutter under turbo acceleration, and it was variable, at times seeming to have gone away. At another c. 4K miles I went in for oil change and mentioned my issue, which had now become CEL whenever I romped on it and the misfire was getting worse. It turned out to be a cracked plug in cylinder 6. But a couple weeks later the misfire was back - another cracked plug. The bad coil pack was destroying each plug I had put in, but not the original plug before the spark plugs change. I have almost doubled my miles since then and everything is working fine. My MO is to wait until something manifests indicating that it's time to change plugs/coils. Ima pretty sure when I do that I will do coil packs as well, since the OE ones will have over 90K miles on them. If I go longer, fine

Here's the arguable thing. A member of the forum, last year, said he had 220K miles on his Stinger, had changed out shocks and struts at 80K and again at 160K miles - as a matter of routine maintenance - but was still on his original plugs!?

Yeah well. I would suggest (as an electrical guy) that the plugs wrecked the coil packs not the other way around.

Cheap aftermarket spark plugs OR simply overtightened cracking various ones on installation. As you say. No problem until you changed the plugs.

In the old days it was broken spark leads by overzealous mechanics.

 

[Snicklefritz]

Yeah well. I would suggest (as an electrical guy) that the plugs wrecked the coil packs not the other way around.

Cheap aftermarket spark plugs OR simply overtightened cracking various ones on installation. As you say. No problem until you changed the plugs.

In the old days it was broken spark leads by overzealous mechanics.

Chicken and egg thing - which came first, the bad coil pack or the spark plug? I had the dealership put in the new plugs, and then the cylinder six coil pack when they found out it was bad. All my plugs / coils are working as designed, all OEM, so, if they are "cheap" that's on KIA.

 

[Alpinesting]

I disagree. There is sufficient evidence that is out there to indicate that voltage leaks with coil packs can damage the plugs. I know this issue is limited to

certain model years, but how do you know it didn't bleed into further models due to supply chain issues due to COVID which could cause this problem to

continue.? I will tell you that in my own experience that we got the suspect coil packs with the boots that developed a voltage leak that caused audio drop

outs and the CEL's when we first bought the car with 15,000 thousand miles on it and it was with the factory plugs. Fast forward to around 5k more miles

after changing plugs and coils, we have no issue. Just my opinion with this and opinions vary.

 

[Alpinesting]

This is the hard plastic model that failed btw

 

[Ah GetFd]

A coil pack is simply a transformer.

It is two coil windings one a primary and one a secondary that are insulated from each other as in all transformers

If one coil were to short. It won't work. It doesn't generate a higher voltage. than it is supposed to.

What a faulty coil can do is cause a plug to foul up as it is not firing at all.

The way a coil works is this. You feed a low voltage, 12 volts onto the primary then you interrupt it. When the collapsing field cuts across the secondary it induces a high voltage, 40,000 volts or more, which is enough to jump the gap in the spark plug and create a spark.

No different to a fluoroescent light. The starter interrupts the current in the ballast (coil), there is a high induced voltage developed by the collapsing magnetic field which ignites the tube. Same principle.

In the old days the interruption was caused by the points. The rotor button in the distributor would direct the current to the right spark plug.

You can't generate a higher voltage than required in the coil so you can't deliver a death blow to a spark plug. A spark plug can handle the 40,000 volts thrown at it. There aren't more turns in the coil so you can't generate more voltage, only less if it shorts out for some reason.

So the most obvious is a spark plug fails, it shorts directly to frame, through a cracked housing through mechanical damage and then shorts the coil.

It may well be a Kia spark plug put in by a simple idiot.

 

[oddball]

Everyone is correct!

In this case, the shitty plastic boot - aka the spark plug wire - was leaky which damaged both the coil and the plug!

The literal coil - the potted transformer - didn't cause the issue, but the boot is part of the "coil" assembly.

 

[Thomby]

Coil packs don't just operate like steady state transformers (low voltage / fewer coils --> high voltage / more coils), because that would require AC current, and you'd need thousands of times more wire on the secondary side.

They're more like transformers combined with an inductor, storing a bit of energy in a magnetic field as DC flows, then when current is cut the collapse of the field spikes voltage. So while I'm not an expert on their internal mechanism, I could imagine a failure mode where a short lets that energy dump do some damage (maybe through misdirected current rather than even higher voltage).

 

[Snicklefritz]

A coil pack is simply a transformer. Etc. ...

If I am understanding, you are saying that each time a plug fails, gets cracked, it is the fault of the plug, not the coil pack / transformer.

So, the same "idiot" broke two plugs, in the same no. 6 cylinder. The "idiot" got five cylinders right, but busted the no. 6 cylinder one. No. 6 cylinder plug failed at two weeks and got steadily worse over c. 4K miles. Changed the plug. Two weeks more or less and it did the same thing. I said, "Look at the coil packs this time". And they did, and they found no. 6 coil pack dead. A few weeks later I went in for my appointment to address this issue, they changed the coil pack and the spark plug again, and it was cracked and burned, aaagain. Please explain this.