Doublebase

I did my spark plugs yesterday and the one thing I noticed was that 6 of the 8 of them had oil on the threads - kind of a light coating. The coils didn't look like they had been bathing in oil or anything, and the electrodes on the plugs didn't look as if they were burning oil, but still some has to be leaking into those cylinders. I don't "use" much oil between oil changes. I don't get misfires. But I assume this will only get worse, so the question I have is...has anyone replaced their's?

There's two mechanical fuel pumps that look like they'll need to come off, and probably a gasket with them as well. I'm just trying to get a feel for how hard a job this would be, it doesn't look too bad, but I've never removed high pressure pumps before. I can probably get the gaskets for somewhere around $70.

And it doesn't appear that the gaskets around the outer edge of the valve cover are leaking, but the donut shaped ones around the spark plug tube. Of course if others have changed their plugs and noticed the same thing - and aren't having issues - I'll let it go as long as possible without changing them.

Devh

If all of the spark plugs look identical and only have a light coating to the touch limited to the threads I wouldn't worry about it.
My other Toyota plugs are the same way when I use to remove them every 10k miles because I was using copper plugs for a little better throttle performance. The Honda on the other hand were bone dry. I believe the source of the slight oily substance might be limited to the combustion chamber and not the donut gasket that surrounds each hole. Excessive oil would concern me but it doesn't seem to be the case.

Doublebase

Good to know, thanks. All the plugs were like that except for one that was basically bone dry (passenger side, furthest to the front).

I do own two Hondas and you're right, those plugs are always dry when I take them out, so I was a little surprised by the Lexus. And there didn't really appear to be any oil on the coil that goes over the plugs and the tube didn't look wet. I'll let it go and just kind of keep an eye on it. Thanks again.

Devh

I'm not 100% ruling out the possibility that there might be a little seepage over a long period of time that finds it's way to the threads however I have known many Toyota owners that have wondered about it as well and it's always a light coating. As long as the electrode looks good and not unusual you should be fine. That little bit of oil on the threads might add to the benefit of keeping the threads from corrosion and then having frozen plugs.

Lexuslsguy

Factory plugs do not come with any coating on the threads. Both NGK and Denso specifically say not to use any anti-seize as this will cause you to improperly torque the plug and potentially damage it. Anyway, I would consult with Lexus or a dealer about it. Valve clover gaskets are a pretty common failures across the LS line.

Doublebase

Yeah I know that these plug companies don't want you to anti seize their plugs, but the only reason why I didn't is because I didn't have any anti seize laying around (or else I would have). I trust myself enough not to over tighten them just because they have something on the threads.

I will keep an eye on it, but it's good to hear that a light coating is not unusual on toyotas. I haven't really seen or heard of many LS 460 owners replacing their valve gaskets, but then again a lot of them on here don't have over 100k miles on their cars. If I can avoid replacing mine, I will, it doesn't look all that fun to do.

roadfrog

I used a very light application of anti-seize when I did my plugs last year. No issues.

Devh

There is truth to the dry torque values being off because of using anti seize . It is advisable not to use a torque wrench and just do it by feel. Snug and then a quarter turn is the way I do it. As long as you don't muscle the plugs too tight you should be ok.
Without using anti seize you risk damaging the threads on removal if the threads become corroded. It's cheap insurance.