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Discussion Starter #1
A quick background: 2002 IS300 manual. Bought the car 2 years ago with 54k on the clock. While test driving the car I noticed that as the car climbed through the rpms, it felt very sluggish and slow. It was barely noticeable at the time so I figured it was ok. This winter the car drew a CEL for a lean code. So I finally got around to buying some plugs and changing them.

So off came the throttle body and my buddy saw a little slack in the throttle cable. He was messing with the cable, only to realize that at full throttle the throttle body opens maybe 20% of the way (while driving, the highest it would open up was 78%). So that would explain why the car won't get out of its own way from a complete stop and probably why the car has a lean code. So I am in the hunt for a throttle body, possibly the 80mm upgrade out of an LS400, but I am seeing that is not exactly a bolt on and go.

Anyway, we get to the plugs and long story short, the front plug of each coil pack is absolutely drenched in oil. The rear plugs of each coil pack were dry though. Anyone have some insight on the problem here? :confused:
 

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Sounds like you have a leaking valve cover(s). Oil isn't conductive and doesn't become a problem until it sits in the valley and becomes contaminated(using resulting in misfires). But why did you take out your OE plug rated up to 120k miles that early, or are you near 90k? I doubt my plugs will ever need changed, I'm at 52k.
Some slack is needed in the throttle cable, remember when you floor it the pedal should be at rest on the backstop and throttle wheel fully engaged or you WILL stretch the cable and break it over time! The butterfly does not open fully horizontal when the max opening is reached, so your throttle body is probably fine. Leave the slack alone, if you don't like the response then do the cable spacer mod at the pedal.

Your problem is because your ignition components are drenched in oil, that's all. Get two new valve cover gaskets and some brake parts cleaner to clean up the mess.

Edit; unless the oil is from overspills when filling it up, that can happen. Look at the side of the valley to see if they are leaking or clean it all up and watch it to see if they do leak. If it is substantial then they are most likely leaking.
 

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Discussion Starter #3
I am at 80k. I changed the plugs hoping that was all that was wrong with it. I thought it could possibly have been an over pour, but there was so much oil in there that an over pour would have been intentional lol.

As for the throttle body, the butterfly has such little movement. The first quarter or half of the throttle doesn't move the butterfly at all and full throttle it is barely open. My buddy used to have an IS and that thing would rip the tires loose from a stop. Mine literally will not get out of its own way until I'm up around 3-4k, at which point it bogs.

I feel like the only reason it can still pick up speed is because the air running through it is keeping it open, as opposed to the throttle controlling it.
 

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Sounds like you have a leaking valve cover(s). Oil isn't conductive and doesn't become a problem until it sits in the valley and becomes contaminated(using resulting in misfires). But why did you take out your OE plug rated up to 120k miles that early, or are you near 90k? I doubt my plugs will ever need changed, I'm at 52k.
Some slack is needed in the throttle cable, remember when you floor it the pedal should be at rest on the backstop and throttle wheel fully engaged or you WILL stretch the cable and break it over time! The butterfly does not open fully horizontal when the max opening is reached, so your throttle body is probably fine. Leave the slack alone, if you don't like the response then do the cable spacer mod at the pedal.

Your problem is because your ignition components are drenched in oil, that's all. Get two new valve cover gaskets and some brake parts cleaner to clean up the mess.

Edit; unless the oil is from overspills when filling it up, that can happen. Look at the side of the valley to see if they are leaking or clean it all up and watch it to see if they do leak. If it is substantial then they are most likely leaking.
This helps as I replaced my plugs two weeks ago because they all had build up of gunk and some noticeable oil. Next to replace on the list will be valve cover gaskets then.
 

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Wouldn't the car smoke at start up if the valve cover gaskets needed to be replaced?
Depends on the smell and color of the smoke.. Usually if it's a blueish tint, it's oil and usually caused by the valve spring seals. It isn't usually caused by a leaking valve cover gasket.
 

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Wouldn't the car smoke at start up if the valve cover gaskets needed to be replaced?
Blowing smoke on startup is a sign of the car running rich(black smoke) or other issues(coolant getting in blows white smoke) or internal oil leak(black). The valve covers would actually never cause smoke on a cold startup, but if the covers are leaking when the car warms up the oil will cause some smoke while it drips down the block onto the headers.

It also depends on the leak and how bad it's leaking. It can leak on the side where the plugs are and seep down into the valley, the oil may not seep down the block or exhaust.

Usually when there is only oil in the valley and it's only around the first three cylinders then it may be a result of oil fill ups, especially if you don't service the car yourself. That's why I always suggest cleaning everything down with brake parts cleaner, rub the ignition cord down with some dielectric grease and see if the oil returns. But in the Op's case it sounds like there is a major leak in the valley.

Edit: I guess I'm late for the reply;)
 

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Discussion Starter #8
Well I definitely plan on replacing the gaskets regardless, but to clarify, the first three cylinders were not filled with oil. The front plug of each pair was filled with oil. So the very first plug, then the 3rd and then the 5th.
 

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Discussion Starter #9
Replaced the PCV valve and MAF sensor and the car runs like new. <$100 fix which was GREAT.

Just need to get around to the valve cover gaskets..
 
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