Found why I had a misfire...

[blupupher]

So borrowed my nephew's '04 Hyundai Sonota with the 2.4 (he is now deployed @ McConnell AFB with another vehicle) since my daughters car is having A/C work done.
Sister said it had a check engine light that came on last time she drove it, but does not know what it was. Has not been driven in over a month.
I started driving, and it had an occasional misfire. Started getting worse the more I drove it. Got on the freeway, and misfires disappeared.
Got home and had a code P0301 (misfire on cylinder 1). Pull the engine cover, remove the plug wire and pulled the plug to find this:



I have heard of this, but never seen the porcelain sperate like this.
Nice easy fix though, a $4 copper Champ plug to get it going again is all it took.

 

[RazorsEdge]

So borrowed my nephew's '04 Hyundai Sonota with the 2.4 (he is now deployed @ McConnell AFB with another vehicle) since my daughters car is having A/C work done.
Sister said it had a check engine light that came on last time she drove it, but does not know what it was. Has not been driven in over a month.
I started driving, and it had an occasional misfire. Started getting worse the more I drove it. Got on the freeway, and misfires disappeared.
Got home and had a code P0301 (misfire on cylinder 1). Pull the engine cover, remove the plug wire and pulled the plug to find this:



I have heard of this, but never seen the porcelain sperate like this.
Nice easy fix though, a $4 copper Champ plug to get it going again is all it took.

If it was me, I'd be changing the rest of the sparkplugs

 

[blupupher]

If it were mine, I would, but being it is just a spare vehicle at this time that they are kinda sorta trying to sell, I am not going to bother.
Plus the plugs still look fine. This one was an odd ball, first plug in hundreds I have changed that had any real issue.

As I said in the video, if the vehicle is still around in 15-20,000 miles, I will probably change them all at that time (and who knows, I may buy it for my son who will be driving in a few months)

 

[Zaedock]

Nice find. I've seen that happen a couple of times. You hit a bump and the engine misfires...lol

 

[dnewton3]

Spark plugs are by far one of the easiest things to change when diagnosing a misfire. They are as prone to failure and manufacturing defects as any other component. It's not necessarily always going to be the spark plug at root cause; is can be a symptom rather than a core issue. For example, if oil gets down into the plug hole it can insulate the ground path and cause an "open" misfire (as opposed to a grounding misfire). But checking the plugs is always a good idea.

 

[JeffKeryk]

Easy fixes ROCK!

 

[DuckRyder]

Yikes - 16 bucks per Laser Platinum.... at least there is only 4 of them...

 

[PimTac]

Assuming the plugs have been changed on this car as it’s a 2004, I wonder if those plugs are genuine Denso?

Some close up pics of the plug cleaned up might reveal the answer.

 

[andyd]

Assuming the plugs have been changed on this car as it’s a 2004, I wonder if those plugs are genuine Denso?

Some close up pics of the plug cleaned up might reveal the answer.

I've broken the porcelain whilst using a regular deep socket instead of a plug socket

 

[GMBoy]

I would have changed them all at that point - just use a $4 autolite platinum or something if you are going to sell.

 

[DZello]

I would have changed them all at that point - just use a $4 autolite platinum or something if you are going to sell.

I tried Autolite XP on my Kia Optima and had to replace them. Tip wasn't even aligned with the electrode properly.

 

[PaxilPlease]

Spark plugs are by far one of the easiest things to change when diagnosing a misfire.

On an ever seemingly decreasing selection of engines. Not true anymore. Manifold needs to be removed, this, that, or the other thing too. Oh, and sometimes even the engine.

 

[CharlesInCharge]

I'd look for a warranty on those plugs and replace them all, if the owner has the receipts.

 

[NitroM3]

I've broken the porcelain whilst using a regular deep socket instead of a plug socket

YES this happens more then people admit even with skilled Auto technicians. Generally it is people that like to hurry through a service job. Sometimes their hast does not appear right away even for several months or a couple thousand miles of engine running.

 

[GSCJR]

The OP has no intention of replacing the plugs at this time, it's not his car. He's simply demonstrating his findings for our benefit. Thank you @blupupher!

 

[PaxilPlease]

I'd look for a warranty on those plugs and replace them all, if the owner has the receipts.

Haha. Who keeps receipts for everything? Plus, it'd likely be more of a hassle and much time spent dealing with it.

 

[PaxilPlease]

YES this happens more then people admit even with skilled Auto technicians. Generally it is people that like to hurry through a service job. Sometimes their hast does not appear right away even for several months or a couple thousand miles of engine running.

Reason number 35 1/2 why I always do things for myself while I am still able to.

 

[NitroM3]

Haha. Who keeps receipts for everything? Plus, it'd likely be more of a hassle and much time spent dealing with it.

I do? Every vehicle has its own record book of everything. Motorcycle, boat, Car, Truck, all the Track only vehicles.
But like you said for some things its easier to just purchase a new one then go to the trouble for only a single spark plug. I just know in the future to maybe not use that brand or type again? Let me tell you I have some rare spark plugs that were introduced and then later pulled off the market by many leading spark plug companies over the decades. As well some interesting ASAIN manufacture spark plugs in my *** collection. LOL

 

[another Todd]

Assuming the plugs have been changed on this car as it’s a 2004, I wonder if those plugs are genuine Denso?

Some close up pics of the plug cleaned up might reveal the answer.

This was my initial thought also.

 

[blupupher]

I'd look for a warranty on those plugs and replace them all, if the owner has the receipts.

Not sure when the plugs were changed. My nephew has had the vehicle for about 2 years, it was his cousins vehicle before that. No idea who or when the plugs were changed.
Car has not been started since I brought it back to their house over a month ago. No reason to change the rest of the plugs or do anything further with the plugs.

The OP has no intention of replacing the plugs at this time, it's not his car. He's simply demonstrating his findings for our benefit. Thank you @blupupher!

Exactly. Was just posting something interesting that I found.

I am still debating buying this for my son, but he really has shown no interest in driving, so not really wanting to buy it and title transfer, registration and pay insurance and such on it to just sit there. I already do that for my truck.