Rough Idle....???

[western99]

Just recently I started to get a bit of a rough idle, in particular at start up. I never used to get this. My car just turned 212k kms. Does anyone have any ideas what could be the cause. I am thinking that it may be my O2 sensor since it has never been changed since I have owned the car. Anyone else have any ideas? This rough idle at full stop is really starting to bug me. Any comments/ideas would be appreciated.

Brian

[SRR2]

Idle control valve may be dirty. May need new plugs. Both my 325 and 535 idle a lot better with the Bosch Platinum (standard type, not the +2 or whatever) gapped to .040". Maybe you're due for a valve adjustment. Or all of the above.

BTW, the O2 sensor doesn't do anything at all until the engine has warmed up almost to full operating temperature. So if the misbehavior is occuring with a cold engine, it definitely ain't the O2 sensor.