When To Change My Spark Plugs?

[TexasEdition]

I know this has probably been beaten to the ground. I just didn't find a quick answer on my search. I have an 04' Sierra 4.8L. I've had a PCM tune for 4 years now if that makes a difference. Haven't checked the plugs yet, but I do have 75K miles on the truck on the stock plugs. Thanks!!!

[txab]

100k is the suggested interval I believe. I just replaced mine at about 70k. One of my wires was starting to act up. Figured I'd replace plugs while I was there. I could've left them a bit longer.

[MikeInCtown]

I did mine at 100k and they looked almost new. I personally would wait.

 

Also, measure your wires and get a set off eBay or buy the MSDs when time to replace. My 04 takes the 748GG wires. $35 on eBay with shipping. $75 at the dealer with trade discount.

[pwall]

I've often wondered when I should change the plugs in my truck......

[agentbook]

I've often wondered when I should change the plugs in my truck......

 

The same time you change your blinker fluid and muffler bearings

[TexasEdition]

I did mine at 100k and they looked almost new. I personally would wait.

 

Also, measure your wires and get a set off eBay or buy the MSDs when time to replace. My 04 takes the 748GG wires. $35 on eBay with shipping. $75 at the dealer with trade discount.

 

I bought a set of Taylor Wires shortly after I got the tune in 05'. I still have the "like new" stock wires in the shop.

[superjim]

I know this has probably been beaten to the ground. I just didn't find a quick answer on my search. I have an 04' Sierra 4.8L. I've had a PCM tune for 4 years now if that makes a difference. Haven't checked the plugs yet, but I do have 75K miles on the truck on the stock plugs. Thanks!!!

 

 

Since you have a tune, I will assume you pay attention to the way it runs.

 

As long as it is running good, and the fuel mileage does not drop, I would be tempted to just leave it alone for a while.

 

The 1999 4.3 that I got rid of in Nov of 06, when I bought my new one, had over 250,000 on the original plugs.

 

It still ran just like it did the day I bought it.

[Z45]

Most 2004 models got Iridium plugs which last a loooooooooooooooooooooooooong time.

 

Never remove the plugs while hot, allow the engine to cool down.

[TexasEdition]

Thanks for all the comments. I will stick with the factory plugs for another 25K. I just wanted to make sure that I wasn't missing something that was out there.

[RB Racing]

 

 

The biggest reason to change plugs at 100k miles is to prevent the plugs & aluminum heads from becoming one. Not an issue until a plug goes bad & you can't remove it without tearing up a cylinder head.

 

 

 

+1

 

I changed my plugs at 50k on my Vette and they were stiff coming out, made sure the new ones had anti-sieze on them.

[bubba33]

I would use only factory plugs, I usually trade for a new truck before it needs plugs.

[mhraracing]

I checked 2 of my plugs on my 02 HD a couple months ago just when it turned 50k and they looked brand new.

[gave20]

I changed mine at 60K and cylinder 8's was completely burnt. I wouldn't wait for 100K.

[killterrorists]

I changed out the O.E. plugs on my 2001 5.3L at 160,000 miles and they looked just fine, they came out just fine too. I replaced them with NGK iridium plugs and MSD wires. I did notice a slight improvement in preformance but nothing drastic.

[zz50]

I had 211k km's when I changed out. Found the OE had .060" gap new and still had .060" gap. The replacement set is now set at .042", the new spec. Runs the same as before, wthout issues. No issue removing. Replaced with AC iridium made in Japan (NGK, Denso?) at half the price. <$5.00 per. Not your standard AC plug, probably uses AC insulators and someone's technology.