2v1g

changed the spark plugs at the local Lexus dealer for $175 with my own OEM plugs. Dealer gave me back the old ones, based on the looks, are my old plugs still in good condition after 60k?

2v1g

I also notice that I get a little bit less delay in the engine power and my engine is little bit louder now

Doublebase

They look fine to me.

Nospinzone

Ditto, they look fine to me as well.

Also, as far as "I also notice that I get a little bit less delay in the engine power and my engine is little bit louder now" I think that's the placebo effect.

Kennyr44

Their made to last 120k so they are only 1/2 worn out.

Doublebase

Exactly, and I did mine at 110,000 miles...they looked like I could have gone another 100k.

DJWLDW

2v

That's what mine looked like last week when I had them changed right at 59,999 miles.. To bad they would not work in my lawn mower (if I had one).

Dennis

roadfrog

Lots of things can "look good" and not function as well as they could. I think 60k miles is a good point to replace plugs, even if they're iridium. Cheap maintenance and an opportunity to see whats going on with your engine. It also allows you to see your water pump (that may be leaking), belt condition/replacement, air filters, etc. I agree - they look fine. But what if they didn't? It would be nice to have a heads-up. Heck...have the tech do a compression check while they have the plugs out if you want.
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2v1g

I can't start my 4.5 hp lawn mower last weekend, so I took the spark plug out and it is covered with black stuff. So I use a sand paper to clean it and put it back. The lawn mower started again.

So I guess that is what your spark plug suppose to be looked like after 60k miles in the picture, you might need to pay some attention if anything dirty than that or covered with black residue?

Doublebase

The black residue is from fuel. A lawnmower has a much less sophisticated fuel management system than a car. A car's spark plugs would never look like that unless there was a misfire.

chetti

Replaced plugs after 250,000 miles. The old iridium plugs looked good and were still working,

Doublebase

​​​​​​​Wow, that's crazy for two reasons...one, that you have that many miles on your LS...and two, that the plugs lasted that long. Pretty cool.

litesoarer

They were replaced on mine at 60K.

roadfrog

Yeah 250k miles is crazy. I find it interesting that synthetic oils can last for 10-20k miles but some to choose to change it at 5k miles. Yet plugs, are viewed differently. Even Denso recommends changing their plugs at 60-80k miles. You got some good service out of those.

One should keep in mind though, that Iridium plugs are not all iridium. The electrodes are still made with nickel, which does not last as long. The other thing to keep in mind is warranty requirements if you have one.

Chetti: How has your car held up after all these miles? Members here love to hear any information on the longevity of our LS's!

chetti

This is a 1999 RX300 AWD so far we have replaced all struts, the exhaust pipe at the front manifold, one spark coil, all new spark plugs, the air mix motor on the heater, both oil control valves for cam timing, water pump, and timing belt