Spark plugs?!?

[Scalded Dog]

So yesterday, I went to the dealer for an oil change (Don't judge me! I can spend $40 there, NOT get dirty, and spend an hour catching up on 18- month- old "Road & Track" issues, OR I can spend $30 and an hour getting filthy, busting knuckles, dealing with carting the old oil away, and so forth).

One of the downsides to getting oil changed at the dealer is the upsell. Sure, they are not QUITE as bad as Jiffy Lube or Econo Lube (which use the oil change as bait to trick people into the fake, expensive, unnecessary, nonsense "repairs"). But, the dealer still wants to make sure that they squeeze as much money out of me as they can.

Anyhow, yesterday's upsell attempt was my spark plugs. I was told that they must be changed at 90,000 or 100,000 miles... otherwise, it'll wreck my catalytic converters.

I've always seen spark plugs (in modern cars) as an item that you change out IF there's a problem with them. It's like a most other parts... no need to replace unless failure has occurred or is imminent. My plugs seem to be fine right now... the engine purrs like a kitten, is smooth, has no misses or lopes or hiccups. Sometimes, at idle, it's hard to tell if the car is actually idling or off.

Am I wrong? Do I need to put "Change plugs" on my list of things to do soon? And... will NOT changing my plugs send my cats to an early grave?

[ytown87]

Potential ability to mess up your cats if you are having a bunch of misfire issues due to bad plugs. Other than that....nope. Doesn't hurt to change at that mileage though but if your car runs like you says it does, you are good

[Venomous]

No judging here. I get free oil changes for 5 years so off to the dealer I go!! I agree, if your car is running good no need to change them. If your at 90 or 100k miles it might be good idea to go ahead and change them. Also, that's something you can do and do not have to go to a dealer for that.

[JerTM]

GM recommends changing them around the 100k mark. They don't require being changed until you develop a misfire or poor performance or fuel mileage. Damage to the cats is POSSIBLE however unlikely unless you have a misfire/poor running engine. Plugs and wires are pretty spendy on an LS motor, but not as spendy as a cat. Personally in my vehicles I change them at the recommended or sooner just cause. I may spend more on maintenance, but that means I spend less on repairs later. I don't like working on my own cars, I prefer to get paid to work on others lol

[Scalded Dog]

I appreciate the comments and the info, friends!

[freddyD]

At 50k they WILL be worn. Run o.k.=yesgas mileage off.

[christianchevell]

compared to the strain a build engine puts out :a stock engines spark plugs are way more longevity prone but also as the engine ages it will develop more and more carbon from engine wear eventually and require changing more often than 50-100k I always found the claims for various cars that a 100k change is all that's required a joke. As many developed problems from that and then changed to recommend more regular changes. If you want you are due for a change and may improve your performance some even. I change mine every couple years with a built engine, and drive about 5k a year. Quite a difference. Hopefully you have the engine running like a clock for a long long time before rebuild, with modern oils it helps for the wear and extends engine life past what used to be the common 100k up rebuild for a cast iron engine with plain old oil 200 k was pushing it. Good luck and happy motoring. Make sure if you do your own plugs you buy the right gapped plugs, as you do not adjust iridium spark plugs gaps if your using them...

[MrChrisLS3]

I'm at 76K and I'll be changing my plugs in the next couple of weeks. Having fresh plugs isn't going to hurt either the engine, or the wallet, so why not? The job itself seems like a breeze in this car compared to some others I've owned.

[Moto-Mojo]

I have a 2001 Yukon. I did change the plugs at 100K even though it ran fine. Being an old dog, this is something I used to do on my 1973 442 about every other oil change - 6000 miles.

I may have missed where you stated your mileage but if it's nearing 100K, just do it.

[Spec]

Changed them at around 60k mi. Glad I did... them stock wires suck! A few of them disintegrated when I removed them... plugs looked good though.

[My 5th]

I changed mine around 60K. When I pulled the plugs the center electrode on about half of them was down to the ceramic tip. I think they were iridium plugs with the really fine tips. The car was running fine before the change, I would have never know anything was wrong with the plugs.

[masterguns95 1LE]

2006 Silverado crew cab 2wd. 264,000 miles. Plugs looked good. Mileage still at 21mpg. Daughter totalled it for me.

[JCunningham]

around the 70k mark is a good time to replace plugs. You may see better mileage after replacing them. You probably wont notice you have to replace them until there really bad. You dont have a old 4.3l you have a high hp v6 thats closer to a race engine and needs proper maintenance. replace with stock plugs.

[JantzenOKC]

Originally Posted by masterguns95 1LE

2006 Silverado crew cab 2wd. 264,000 miles. Plugs looked good. Mileage still at 21mpg. Daughter totalled it for me.

I've been told these new iridium plugs GM is using don't really wear and they could potentially be ran forever. I've changed some pretty high mileage ones that still look perfect so I could see that being the case. I'd probably still change mine at 100k though.