Rough Idle

[john neuhoff]

My 95 530ia with 156K was giving the check engine light. After numerou$ visits to my indy, replaced O2 sensors, decarbonized, disconnected the cold start air pump, replaced the air flow sensor, it was running fine.
Now, 3-4 months later, I have episodes where the engine idles roughly while in gear at a light, a/c makes no difference, putting in neutral helps a little but still there, although it runs well as I accelerate. At times it will be fine, other times it's back. It seems independant of engine temp or climate.
Any thoughts on where to begin?
Thanks,
John

[john neuhoff]

Oh yeah, the stomp test shows all clear
John

[Jon K]

Oh yeah, the stomp test shows all clear
John


Idle Control valve?

[Jeff N.]

Idle Control valve?

[john neuhoff]

I'm not familiar with that, I'll look in Bentleys. Any clues to offer?
Thanks
John

[john neuhoff]

The block was replaced at 100K, so alusil, right?
John

[632 Regal]

also could be the PCV plate at the back of the intake... total PITA to fix but only 40 bux.

[andyman32]

I have the same thing, very rough idle. I'd think it was leakdown if I didn't know it was a alusil block replaced sometime in '98 or '99. I've got new motor mounts on order (my PS pressure hose was leaking all over it), but it's probably something more involved - idle control valve or f*ed up timing or something.

[john neuhoff]

thanx