weird idle with video

Just had the head changed on my 2000 XJ. My idle was rough before and it's the same after. i was hoping it would be an manifold leak or something but it's the same. Here is a video. It sounds like something is opening up and the engine revs a little higher then settles back down, but the whole engine is idling rough to the point you can feel it all throughout the jeep. There is no check engine light on. ideas?

http://www.youtube.com/watch?v=9xbUOFxRbro

Did you have the a/c on in that video? The compressor turns on and off, especially if the a/c knob is on 1 or 2. Every time the compressor activates, the engine automatically lets in a tad bit more air into the intake; I believe through the Idle Air Control Valve. That's what gives you that idle.

Yep, realized the defroster was on low. Now, for the rough idle, I'm running a can of seafoam through the tank now, it hasn't helped.

I have a small exhaust leak on the flange where the cat meets the muffler. I can hear it and there is condensation dripping there. Would this cause a rough idle? The leak is post cat/02 sensors.

Is your check engine light on?

I believe the 2000 xj has 4 oxygen sensors at the two piece header. There are two before the pre-cats on each header and two after the precats on each down pipe. Here are the top two. This pic is with the intake manifold removed. The o2 sensors read those two smaller catalytic converters, but they don't read the third bigger catalytic converter. However, I get a CEL light now and then and I search for codes with an OBDII scanner. The scanner would show me that I have a "minor exhaust leak". But, then it goes away.

shaman1204 said:

Yep, realized the defroster was on low. Now, for the rough idle, I'm running a can of seafoam through the tank now, it hasn't helped.

I have a small exhaust leak on the flange where the cat meets the muffler. I can hear it and there is condensation dripping there. Would this cause a rough idle? The leak is post cat/02 sensors.

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I don't think an exhaust leak would cause rough idle. My dad's old 98' 4.0 cherokee had a small leak at the header and it idled perfectly.

Yeah thats definitely the ac kicking on and off. Mine does that too, pretty sure its normal it is pretty loud though.

Looks completely normal. I was expecting the RPMs to be all over the place, but yours only jumps when the AC is kicked on and off, which is fine.

shaman1204 said:

Yep, realized the defroster was on low.

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You're also low on freon as it shouldn't be cycling that fast. This time of year, you can probably find R134 on clearance at Walmart. I used to pick them up for $2 a can for my ZJ that had a really slow leak.