Most miles on original spark plugs ?

[PostalBound]

2007 Hyundai Sonata 3.3 L with original plugs went for 143,670 miles on the original Iridium plugs. They still looked good and car averaged about 24.5 mpg. Almost wish I left them alone. So far my mileage has gone down .....

What is the most miles you've seen on a set of plugs ?

 

[Oregoonian]

Right now I have almost 104K on the original double plats.....on my signature vehicle.

Just purchased....four **Autolite AAP 103's (Double Plat.)....and will change out the originals in a few months.

** Autolite has a $1.50 rebate per plug....and I paid 4.49 at Autozone.

 

[FowVay]

My BMW 323i is at 13 years and 75,000 miles on the iridium NGK's that it came with. They're not scheduled to be changed until 100,000 miles (no time limit listed).

 

[tangojetta]

122,000 miles on my 06 Ford Freestyle, still look pretty good when I took them out.

 

[MNgopher]

Had about 145,000 on the factory platinum plugs in my '97 Explorer 4.0 SOHC when I changed them. Amazing how much smoother she idled after that... Never assume the previous owner has done anything!

 

[2Fast4U]

Was looking at plugs yesterday on rockauto. They show $4 per plug rebate on bosch fusion plugs. Mine are about 5.50 a plug before rebate. This looks like a fantastic deal. Vehicle is currently at 95k with original iridium plugs.

 

[LckydevL]

I went 100k on the OEM ACDelco iridium plugs. Looked fine when I replaced them with Bosch Platinums. The Bosch plug did not do well in the 4.8 engine. Replaced at 50k and 3 of them had no diodes? that were visible.

Went back to the OEM iridium plugs and am looking forward to another 100k.

 

[TFB1]

A friend recently had '00 Chevy van towed into his shop that had 263K mi on the original plugs... The reason it quit was the coil wire burned through and was arcing to a bracket, with a new wire it ran decent but much better with a full tune up...

It generally isn't a good idea to run plugs for over a 100K miles... As they age the coil(S) must build higher and higher voltage to fire them, so often the coils or plug boots fail because of the high voltages... I change my plugs at around 50K mi as I've seen plenty badly burned by 75 or 80K mi...

 

[oppirs]

Caddy was bought used, I don't how long in or/if originals. This pix shows what happens just by age/road salt, ect. After the front 3 broke this way, I gave up. Caddy runs fine even with these (5) worn out plugs.

 

[3311]

About 150k on both trucks below, 06 are original and the 04 are autolites IIRC. When I changed the plugs in the 04 below at 100k they looked great. I'm not going for any endurance record, just haven't gotten to it.
Just did my wife 08 Mazda 3i 2.0 at 100k miles and they looked great as well.

 

[TFB1]

Originally Posted By: oppirs
Caddy was bought used, I don't how long in or/if originals. This pix shows what happens just by age/road salt, ect. After the front 3 broke this way, I gave up. Caddy runs fine even with these (5) worn out plugs.


The bluish paint dab on the tip would indicate it's original, it's not on replacement plugs... I've seen Fords with pink dabs on the plugs...

 

[oppirs]

Originally Posted By: TFB1
The bluish paint dab on the tip would indicate it's original...


Jeez..... 126k on coppertops and 23 years!!!! I don't want too, but these other (5) gotta go.

 

[TFB1]

Originally Posted By: oppirs
Originally Posted By: TFB1
The bluish paint dab on the tip would indicate it's original...


Jeez..... 126k on coppertops and 23 years!!!! I don't want too, but these other (5) gotta go.

Soak them a few days with PB Blaster or similar...

 

[oppirs]

The pix shows the base soaked in PB blaster(did it over 3 days w/heat cycles). The hex is so thin now a couple ft.lb. and it snaps. That why I gave up.

Thanks about info on the blue paint. Didn't know that.

 

[TFB1]

Originally Posted By: oppirs

Thanks about info on the blue paint. Didn't know that.


An yer welcom'

I'm guessing the dab could be any color, but as far as I know it's only on OEM plugs, the friend who serviced the Chevy van I mentioned told me about it...

 

[Vikas]

Honda Odyssey 99 @ 152K Original Plugs

Close-up of the two plugs

 

[PostalBound]

Vikas,

That picture is what my NGK Iridium plugs looked like. Some wearing and that white crud on them but overall very good. I'm surprised at some of these pictures and knowing these things can still fire.

One thing I can safely say. NGK makes a darn good spark plug.

 

[SteveSRT8]

Factory AC Delcos in a 2004 van ran over 200k miles, never a misfire and drove perfectly.

Replaced with NGK AC Delco. Why any other?

 

[Vikas]

Yes, and after replacing those plugs, the van ran still the same i.e. I did NOT get the extra fifty horsepower by replacing the plugs or replacing the timing belt or the water pump. I was majorly disappointed; only if I had put the E3 plugs

 

[artificialist]

I have dealt with people who let their plugs go over 150,000 miles. What often happens is that the ignition coil gets destroyed trying to spark across such a huge gap. By the time they have gone that far, many cars have P0420 codes because the excess fuel harmed the cat.