blsnelling

iTrader: (4)

These plugs came out of my trucks original 5.3. It has 78,000 miles and runs great. It does not smoke. 7 of the plugs were clean, but #7 had all these deposits on it.

Mart00SS

iTrader: (19)

looks like #7 is lean and detonating, could be a few different things, clogged injector, dirty maf causing a lean condition, Fuel pump low pressure or clogged filter, I'd look into it asap because if the ringland isnt hurt yet it will be next to fail.

blsnelling

iTrader: (4)

Thanks for the reply. I don't think it'll be the MAF, fuel pump or filter, because only one plug looks like that.

So lean and detonating would cause oily looking buildup?

NXZ28

iTrader: (45)

Looks like a bad valve seal to me or a worn valve guide.

disturbthepeace

looks like it's burning a little oil and oil consumption will cause detonation, I would give your pcv system a good look over. I have seen more then a couple 5.3's that eat a little oil even under 100k.

Good times
Joe

blsnelling

iTrader: (4)

In other words, I shouldn't be too quick to yank that head a rering that cylinder? I'm going to do a leak down test on all the cylinder this evening.