Spartan7

iTrader: (7)

These are out of my 01 Silverado LQ4. Completely stock engine, 180k miles. Unknown miles on plugs, this is the first time I've removed them since I bought it. It's always had plenty of power, no real issues. They don't smell like fuel or look fouled.

Layed out the way they'd be installed. Closest to camera is front of car:


Bottom is front of engine:


Close up of #6, the only one that has a really crusty ground strap:

01ssreda4

iTrader: (96)

I'm not big on reading plugs, but they aren't very old because they look like a copper core plug with virtually no wear. How long (mileage wise) have you owned the truck?

3rdCoastPowerSports

iTrader: (5)

they look ok to me, dont know about the crust though

poltergeist 02

iTrader: (65)

they are telling you to put NGK TR55 plugs in.

3rdCoastPowerSports

iTrader: (5)

hahaha i run those plugs, good plugs

3pedals

iTrader: (3)

the crust is just deposits from impurities in the fuel, I wouldnt worry about it. I do think that the plugs are toast, as the electrodes are rounded off. I'd replace them with TR55's

technicalninja

iTrader: (1)

Those look worn out but normal. The color is fine. the sloped rounded off tips look 50-60K miles.
I'd replace them with the NGKs and re-pull in 1 year to re-check.
The crustiness on 6 could be from a slight oil consumption or more likely an injector with a dirty pattern. If the injectors have 180k on them I'd either replace or pull them and have them ultra-sonic cleaned.

Those actually look pretty good for "unknown" history plugs.

chrisfrost

iTrader: (8)

Did'nt anyone notice the # ,,,,,,,,,those are for gen1 like a 327 or a early 350/360hp ,,,,,,,,,R44ts the "Mighty" plug ,,,,,,,,replace with NGK's or Bosch platinums or if You have the money the factory or equivalent iridium plugs ,,,,,,,,,they don't look bad at all ,,,,,if they were the called for plugs I would clean/sand/check gap and reuse .

Spartan7

iTrader: (7)

Ok, good to know. I've only put about 5k miles on the truck since I bought it. I know a lot of you guys like NGK, but I'm partial to Autolite, so that's what I'm replacing them with. Thanks for all the input.

Syris

iTrader: (1)

Beside the crust buildup, they all have good color which means its getting proper burn

richard david

327 plugs use a 13/16 socket and other Gen 1 plugs had a short thread reach except for the later vortex motors