Kia Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Since this is my first post, I'd like to thank the members for the great info.

We have a 2011Kia Optima EX 2.4Lf.

Currently we have just a bit over 15,000 miles on the beast.

The biggest problem that we have with the car is the POOR gas mileage.

This car replace a 2003 Pontiac Bonneville that had a 3.8L V6 that had a bit more low end torque and it got 25 mpg for the driving we do. Rural driving at 50 mph mostly(35 miles/ per day) and 4 miles of interstate(3 miles per day)


The Optima on the same route never got over 24 and was down to 22 in the cold winter temps.

Seeing the Spark Plug gap post a few weeks ago, had me wondering if this was part of the problem. The car always seemed to sound strange while idling. A weird tinny idle....

So I used my spark plug socket, and pulled out the first plug.... damn, the gap was very close to 0.042"
Guess that was not it.
Also the color of plug seemed to be normal... a light brown color insulator.

On to plug #2 gap was fine.....

At this time, I figured that I should get the plug part number, so I removed it from the spark plug socket..:eek:
I've Never!!!! seen plugs that looked like this.... Ever..


I pulled all of them and they were all the same.
At first, I thought that DENSO, painted on flame/smoke onto the porcelain.
of the beast!, but after I got my reading glassed, I saw that it was not artwork!

These were electrical burns / arching.


I then inspected the coil pack/boot. It was dry, but not burnt.

The connection in this boot/coil is very strange, it is a coil spring that touches, just the top of the metal on the spark plug. Nothing like what most have seen.
I then thought that the plug was not contacting the spring well enough. But after measure the depth of the spring in the boot and the dimension of the plug, the spring IS compressed 0.300".

I did not have a set of plugs, so I had to put it back together. But, I added Dielectric grease to the boot and to the top of the plug.

Since I've done this, the Overhead has increase up from 26 to 28 mpg on a tank that was under half.

Once we run a few fill ups through, I'll report back.

Power seems up just a bit also!

Another good reason to check your plugs.

Thanks again!
 

·
Premium Member
2020 Hyundai Palisades
Joined
·
2,970 Posts
well from the pictures it appears to me to be a burnt on oily residue on the insulator. i would think if it was arcing it would be at metal body and it would be burnt and pitted looking.
 

·
Registered
10 Optima LX, 07 Rondo EX, 89 Chevy C1500
Joined
·
1,410 Posts
Every plug I pull out of a 2.4L, GDI or not, looks like those. That's normal. Just adding dielectric grease isn't going to alter your mileage.
 

·
Registered
2012 Kia Soul +
Joined
·
34 Posts
Those plugs look perfectly normal for C.O.P wear.

My old Cavalier (turbo'd making nearly 400HP) used the same COP style with a spring connecting the plug to the module.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #5
Every plug I pull out of a 2.4L, GDI or not, looks like those. That's normal. Just adding dielectric grease isn't going to alter your mileage.
If you pull many Kia plug, do you work at a dealership?
If so, contact Kia for a response on a solution.

This is not normal.

Also, it is not oil residue. I took a scotch brite pad with carb cleaner and wd-40. Neither took it off.

With a magnifying loop, there is pitting in the porcelain. None of the metal is affected.

Also, as we all know, modern engine controls adjust many parameters very often. My theory is that a slightly rich condition is occurring( tail pipe soot/ black) and the computer is trying to adjust for the rich condition as be as possible( light tan color of plug tip).
With a direct injection engine, ( such as the skidoo sdi and di 800's, the plug color does not look like engines without this technology( ie carburetor ).
They sdi and di run as lean as 17:1 at times. The plug color is closer to a off white than tan.

Not trying to start an big argument, but this direct injection motor should not have exhaust tips that are black and mileage that is so poor.

Please contribute what other factors are causing these issues( poor factory calibration/ programs?, marginal sensor accuracy?)

Has Kia addressed any of the issues with tsb ?

Only if EfiLive worked on Kia's, I could data log and tune it out.
 

·
Registered
Joined
·
226 Posts
Every plug that I have removed from a Kia (11 year tech) look that way to some degree.

You must determine that there is a problem before demanding a solution.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7 (Edited)
Poor fuel mileage.
Soot on the exhaust of a "effiecent" di engine. (lol)

Only "demanding" when my findings and possible causes are discounted without a solution or "this is normal" -dealer response.

Any suggestions to to get 65mph highway driving from 25mpg up to 30+?

If the engine is not running rich and the car is not burning oil, why are the exhaust tips blackened with black slim?

Have any other solutions/ causes been found to help these issues?






Sent from my Autoguide iPad app
 

·
Registered
2017 sportage sx
Joined
·
448 Posts
Any suggestions to to get 65mph highway driving from 25mpg up to 30+?
Sent from my Autoguide iPad app
Are you using the ECO function?
I get 28 highway MPG from my turbo which I do not baby. Same black tips which I think is how the warm-up phase is mapped.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #9
We have used Eco and have not noticed a difference in mpg.

Got a new set of tires on Wednesday.
We'll see if mileage is affected. Went with a set of Yokohamas.

driod
 

·
Registered
Joined
·
2 Posts
Poor fuel mileage.
Soot on the exhaust of a "effiecent" di engine. (lol)

Only "demanding" when my findings and possible causes are discounted without a solution or "this is normal" -dealer response.

Any suggestions to to get 65mph highway driving from 25mpg up to 30+?

If the engine is not running rich and the car is not burning oil, why are the exhaust tips blackened with black slim?

Have any other solutions/ causes been found to help these issues?



Sent from my Autoguide iPad app


Soot on the exhaust is completely normal. It's carbon build up from the fuel burning. Lean condition still produce soot. Every car on the road has it, some have it more than others.

The spark plugs look and are fine. if they were in fact "arching" as your title describes the car would be running very odd and funny. Now days spark plugs have a resistor type of plugs due to the ignition setup. You can put a non-resistor type plug in there and it can/will damage the electronics on the car.
 

·
Premium Member
2017 Kia Niro Touring w/Tech Pkg, Blue/Grey
Joined
·
1,956 Posts
Soot on the exhaust is completely normal. It's carbon build up from the fuel burning. Lean condition still produce soot. Every car on the road has it, some have it more than others.

The spark plugs look and are fine. if they were in fact "arching" as your title describes the car would be running very odd and funny. Now days spark plugs have a resistor type of plugs due to the ignition setup. You can put a non-resistor type plug in there and it can/will damage the electronics on the car.
+1.

A lot of uninformed opinions on forums.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #13
Soot on the exhaust is completely normal. It's carbon build up from the fuel burning. Lean condition still produce soot. Every car on the road has it, some have it more than others.

The spark plugs look and are fine. if they were in fact "arching" as your title describes the car would be running very odd and funny. Now days spark plugs have a resistor type of plugs due to the ignition setup. You can put a non-resistor type plug in there and it can/will damage the electronics on the car.
:confused:
So a non resistor plug would not arch, but would damage the "electronics"?

Not sure why you would recommend that:confused:
 

·
Premium Member
2020 Hyundai Palisades
Joined
·
2,970 Posts
:confused:
So a non resistor plug would not arch, but would damage the "electronics"?

Not sure why you would recommend that:confused:
he didn't recommend it he pointed out that it can and will cause damage as when the spark jumps the gap it causes a high frequency burst of energy and this is known as RFI (radio frequency interference) so without resistor plugs you would experience lots of static popping noise in radio and also cause interference with other sensitive electronics computers etc.
 
1 - 14 of 14 Posts
Top