1oldES300

Hi all. My car is idling rough. I changed all the spark plugs (the ones in the back too). One cylinder is drenched in oil... The PCV valve is changed too. My idle is ok at Park and Neutral (about 1000), but when I shift it to Drive or Reverse and stepping on the brake, the rpm goes down to 700, then 500 then sometimes drops to 0 and the car stalls. Usually the car stalls when I'm at a red light so I have to step the gas pedal a little so the rpm would stay at 1000 (and brakes at the same time). What else is there to look at that would cause the car to idle rough at Drive/Reverse?

calichris

iTrader: (2)

try some seafoam

fireman155

i dont know much bout lexus but that sounds like what my f150 did when my coil pack was going out

ps do your oil pressure drop as well when the rpsm drop?

Slooooooow

iTrader: (1)

Seafoam is almost always a good idea.
IAC clean-up comes to mind.
A search brought these up:
Read this one
and
https://www.clublexus.com/forums/sho...d.php?t=326426

llcoolpass

warning, this could be a failed head gasket.

if the oil was filled only in the spark plug tube, not the cylinder [not completely clear by the way you said it "One cylinder is drenched in oil..."], then you might just have bad ignition spark, and maybe some other problems cause by the oil.
otherwise, if there was a lot of oil in the combustion chamber, then headgasket is a possible

BadViper22

+1 For cleaning your IAC valve.

llcoolpass

yes that could be it, but didn't it seem to coincide more with the oil thing?

Slooooooow

iTrader: (1)

I agree the cylinder being "drenched in oil" is an odd curveball. Could be related; could be the symptom of another issue.

This crap is just a fun puzzle ain't it?

llcoolpass

its fun assuming the person on the other end eliminates the possibilities honestly for us

its also not fun if it's a bad head gasket, even a bad valve cover gasket means some work is entailed....

well yeah fun for us to sit here and type this stuff

1oldES300

Sorry I have been gone.. But I already cleaned the IAC valve, and it still idles rough. About the "drenched oil" thing, I mean that I stuck the dipstick into one of the spark plug tubes and there was oil in it (with the spark plug removed). The tube is the one located on the far right (driver side, back valve cover). I also sometimes hear clicks and the engine shakes a little when I hear them. I'll look into the cap and rotor. Thanks for your replies.

llcoolpass

clicks could be sparks, if the electricity doesn't reach the spark plug properly, due to oil contamination of the spark plug wire, the spark will want to go somewhere else, causing electricity to jump out of either, some, or all of: the cap, rotor, wire, etc.