Try this.
Normal wear with a light tan color is the way they should look after a lot of miles. As stated anything else will indicate some engine malfunction
Reading plugs is just not the help it used to be in the old days of leaded gasoline. Race cars using high octane leaded fuel can still make use of the old techniques.
Unleaded fuel doesn’t color the plugs very well so scan tools are your best bet these days as @asemaster says. No-lead fuel just doesn’t color the plugs much. Sooty plugs tell you that cylinder isn’t firing, oil fouled still tells you rings or valve seals need service and rounded electrodes just confirm what your fuel mileage already did.
That said, I still always look closely at the plugs I pull out to confirm what everything else tells me.
This is like asking someone to Read a Book after it already burned up in the fire.
Like the others stated… Pull the plugs DURING their useful lifetime and then they can be read. What we have here are a bunch of worn OUT plugs. In all seriousness you can learn a few things from your plugs but if you want a health check on how things are running …read them earlier.
Blackbird
I got the car from my father, by his memory the plugs were changed at the 100,000 mile service. Currently at 180,000 miles.
The plugs came out with no trouble and the car is running is great now.
This all started after I noticed some hesitation or choppy acceleration after the upper radiator hose burst. Eventually I did get an OBD code for misfire on cylinder 7.
Obviously they needed to be changed any way, but is misfiring after a coolant loss event like that common? I didn’t see any antifreeze in the spark plug wells but will get down in there and foul the plugs?
You are associating two separate events entirely… It is possible to have a misfire IF the plugs and wires and distributor cap get wet with coolant… Perhaps that occured to make you associate the two? Hmmm… Anyway…you should be good to go plug wise at this point…and since you repaired the Rad hose already you are go to go in that department as well. But one did not cause the other in your instance.
Blackbird
Sounds like the coolant went everywhere. Yeah, that can affect the ignition system. It’s probably dried out by now, and, combined with the needed spark plug change, has left you with a good running car.
Personally, if this 2000 has a distributor based ignition system, I’d replace the distributor cap and rotor just to eliminate the possibility of any coolant residue causing a future problem. If it’s COP (coil-on-plug), let sleeping dogs lie.
One critical thing to read on plugs is the brand and part number. It is advisable to replace plugs with OE parts. There are a few exceptions that gear heads have found worthwhile but for the DIYer a great deal of time and money can be wasted installing various “high performance” plugs that often don’t work as well as the worn out plugs they replace.
+1 to Rod’s post.
Flame propagation is a key element of consideration at the chamber design level. Change the point in the chamber at which the flame originates and your chances of improving performance are extremely slim at best. More likely, you’ll end up with operating problems that’ll make you regret having experimented. An inadvertent change in heat range of the plug by switching to a “designer plug” could even damage the engine.
The advertisements for “designer” plugs make it sound like chamber design is unimportant to the engine designers, like it just ends up however it ends up. The truth is exactly the opposite.
“the plugs were changed at the 100,000 mile service. Currently at 180,000 miles.”
Those look like conventional copper plugs to me.
If so they have a right to be beyond worn out at 80k miles.
If they are platinum plugs (I’m not familiar with how they look) 80k is a long time for them as I understand.
The deposits might be due to your father driving very gently over the years.
Platinum tipped plugs are indistinguishable visually from copper core plugs.
Irridium plugs will have a very thin center electrode of a very black color. They’re visually clearly different.
Those plugs in the pic look like copper core plugs to me; and worn clean out. On average, copper cores are good for about 30-40k miles if everything else is fine although they appear to run fine for longer than that.
Platinums can go 50-60k miles all depending; and yes I’m aware of people who run them for 100k miles and change with no apparent issues; at least on the surface.
I inspect the old plugs as they come out. Unleaded gas and detergents in the current gas usually mean the old plugs are still pretty “clean” looking when they come out. A dark ceramic electrode indicates significant misfires in that cylinder. A “wet” plug is oil fouled, or excess fuel and that means trouble in that cylinder. None of this is “conclusive” but is evidence of a problem with more diagnosis required.
The spark plugs in the pictures read “Motorcraft Platinum AGSF 32PM”.
This 4.6 Ford came with 100K mile platinum plugs…After 100K miles they can be difficult to remove and will be burned down to a nub, with a HUGE gap that can easily mis-fire and damage the C.O.P.'s…A new set of plugs ALWAYS results in a noticeable performance improvement in these “Panther” based cares if you leave them in for 100K miles…
Misfires and worn out plugs … could happen. The symptom I usually notice first if I don’t change the Corolla’s plugs on schedule is pinging, especially when accelerating up steep hills from a stop; the pinging starts at about 20-30 mph.