Getting ready to do a tune-up on my 1998 Siverado 5.7L. Any advice when it comes to spark plugs. I can replace the old ones with OEM plugs fairly cheap. Any advantage to using more up to date plugs such as iridium type? Or should I just stick to tried and true?

 

Keep in mind plugs described as platinum or iridium are only referring to a coating on the electrode - the core of the electrode is still just basic copper.

The advantage to using platinum or iridium plugs is the service life - the electrodes aren’t supposed to wear out as quickly as traditional plugs where the copper core is directly exposed to combustion chamber temperatures.

That said, any rich/lean running conditions or issues with the PCV system causing excessive blow by and/or oil consumption are going to foul the plugs no matter what they’re made of.

 

I can remember a time long ago, when leaded gasoline and engines that might last 150K. We had to change or clean plugs with this sand-blasting unit every 25,000 miles, gap them, set the points, or replace them.

Man, I'm getting old or what?

 

I know what you mean. My auto enthusiasm started with those engines, though points were being replaced by ICM’s by the time I started driving. It’s not even recommended to clean or re-gap plugs today.

I see them every now and then as I have a few customers that own them for cruising around in the summer. They’re good for reminding me how they operate.

 

Thanks, I’m going with ACDelco. Ordered online, came in today. Disappointed to see on the package Made in China. Wouldnt have bought them had I known. Trying to decide if I’m going to return. Know of any American made plugs?

 

None that I’m aware of.

 

Yeah, I only cleaned the old spark plugs in HS auto-shop sand-blaster. That lead wasn't good for spark plugs or children. I just changed the plugs on my 2015 2.5 liter Malibu at 98K. They could have lasted another 25-50k they were so clean. Back in the day I'd have to change the plugs at 3000 miles in my father's Chevy C-60 with a large block 366 cubic inch motor due to the lead. The back plugs were a
real B**th to get to. Had a cartridge oil filer, so changed oil, filter, plugs, and points at the same time.

 

You probably already used the ac delco plugs in your truck by now but just for your information, the NGK plugs are now manufactured in West Virgina,usa.
Hope this helps.

 

Welp, I frakked up. Was going to go NKG, but went ACDelco. All were gapped to spec and the the old ones didn't really need changing. Should'a pulled plug #1 out first. Had I done that I would not have even changed them at all. They were only very slightly worn, but still in good shape. Not touching them again.

And yes, they were iridium plugs, as were the new ones. Got them on my 98 Chevy K'-1500 (NKG's Iridium plugs) and they are clean as a whistle, as my Chevy 25-year-old motor doesn't burn any oil at all. Must have got the high compression pistons and piston rings, unlike the junk 5.3 liter Chevy motors. I've heard those noises they make and it's just awful. Did Chevrolet really believe that a loose motor would lower emissions or save fuel? If so I should have become an automotive engineer for General Motors.