When to replace OE spark plugs?

[philipp10]

Originally Posted By: pb
guys, while the plugs may be fine, there is the concern that seizing may occur at long durations. i think it's absurd to expect 100k unless your taking it to the dealer for the plug change.


So you expect seizing to occur? Maybe so but with that logic, wouldn't it occur at 50k just as easily then at 100k?

Personally I would pull them at 100k and if they looked good, re-gap and throw them right back in, putting anti-seize on the threads. I have not purchased a plug in 15 years....I got sticker shock last time I saw what they go for now...lol

 

[slacktide_bitog]

Originally Posted By: pb
guys, while the plugs may be fine, there is the concern that seizing may occur at long durations. i think it's absurd to expect 100k unless your taking it to the dealer for the plug change.


Spark plugs usually come with some special plating that acts as an anti-seize, and NGK's definitely have it. In fact, that's why they say to never use anti-seize on any NGK spark plug.

And yes, iridium plugs do last for at least 100k if not more. Toyota actually specifies 120k.

 

[GenesisGuy70]

I changed the factory plugs in my Taurus at 99K miles. I believe they were iridium. They had fired so much the little bent over part had grooves wore down into them.

 

[artificialist]

I replace spark plugs when I can feel the engine lose performance.

Sometimes I get a car with 60,000 miles with failing plugs, even if those plugs were supposed to last 100,000 miles.

 

[Kira]

I'm looking at his now with a 2001 Chevy Camaro w/95K.

REMEMBER: This is an '01 from GM. Local Chevy dealer parts dept. had a platinum and an Iridium listed.

I'm going to take a look at what's in there.

The BOZO garages this car was taken to makes inspection a wise move.

IF they were iridiums there's nothin' to stop a thieving swap to cheapies. As in, "Hey, where'd my Volvo battery go?" Kira

 

[Trav]

+1 on sticking with the owners manual. Don't wait until you get noticeable misfires or high misfire counts on a scan tool, the cat is slowly being damaged.

 

[The Critic]

Originally Posted By: hattaresguy
If you plan on keeping the vehicle for less than 150k I would never change them.

I changed my last set of plugs on my Silverado at 90k and they looked new. I never plan on touching modern plugs again unless one fails.


+1

Most of the plugs that I've changed, at least the long life iridium ones, were not necessary.

 

[Joe_H]

Believe it or not, the 09 Chevy 6.0 Box Van at work went to 380,000 miles on the original plugs before they got changed.

It developed a misfire and went into the shop where it was determined it had a bad coil. The mechanic then pulled a spark plug and was shocked at how badly it was worn down. They were still the originals. He went around the shop showing it to everyone. The worst they had seen..They were amazed it even ran.
BTW, it now has 395k on it and still runs great. The trans took a dump at 200k, but the engine just keeps going.

 

[howie2092]

OEM plugs from my 2006 Durango 4.7L with 100k miles. Gap on used plugs measured .060" -.120", should be .044". This vehicle was bought used at 93k with minimal maintenance by the PO. New plugs/filters/fluids did wonders for this truck, MPG- and power-wise

New NGK V-Power plugs were around $12 with coupon. Well worth the $$ and time. I usually replace at 75k intervals if they need it or not.

 

[raytseng]

The only reason I'd have not to change at 100k, is if i had plans to sell it soon or around the indicated interval, and I would not get any return on my maintenance "investment".

 

[hsd]

Wait to 100k then pull one of the easy front plugs for inspection. If it looks good and the gap is within spec put it back and run it to 125k? then pull a different front plug for another inspection. I ran my old 2000 Accord platinum plugs to 140k before changing them. I should have left them in, as it ran no different afterwards.

The ECM will detect misfires before you will feel it and before it does damage to your cats.