jhomer42

Hey all,

I recently replaced five of the spark plugs on my es 300 99. I can’t reach the fifth in the back (#3), so I’m soon to have a mechanic do that for me.

Do the plugs look ok? Car has almost 190k miles on it, and I’ve changed the oil regularly, and maintained everything else as much as possible since 160k.




Thanks

LeX2K

Too much carbon try running higher quality fuel and you probably have a valve cover leak that's why the threads are oily. I hope you put in genuine Denso plugs. All 6 plugs can be changed without removing the plenum it just takes patience and the right length of extension and swivel.

jhomer42

Thank you for your reply. I put in Bosch double iridium I think. Are those not as good?

I tried to replace #3, but I’m worried I’m going to strip the bolt holding on the ignition coil.

So I should replace the valve cover gaskets to fix the leak? Is that major issue? Can I wait a couple of months to fix that? I haven’t noticed any oil leaking.

Thank you!

LeX2K

No good, only Denso SK20R11 also known as Denso 3297 work properly in these cars. Don't buy anywhere but a real Toyota dealer everything else is likely counterfeit. That includes Ebay, Amazon and now from what I've seen Rockauto is not immune to fakes.
It's not urgent but if the leak gets bad enough the ignition coils will be damaged, hot oil breaks down the plastic housing.

jhomer42

Do I need to adjust the denso plugs at all before installation? I was going to put dialectic grease between plug and the coil. Do I need to put any kind of gel on the threads of the plug? Thanks.

LeX2K

No don't mess with the gap it is already set, doesn't hurt to smear dielectric grease on the coil boots. Can put the same grease on the plug threads so they don't go in dry, don't use anti-seize!