Idle speed and brief "dip"
 

What's the normal idle speed for the 3.0si? I feel like mine is too high - probably at 850 RPM. Also when in drive and foot on the brake the idle drops very briefly several times. It's just a quick drop and goes back to normal - sometimes this doesn't happen at all and other times it does it 2 or 3 times. Any ideas?

Mine shows about 600rpms with AC OFF and 800-850 when the air conditioning is ON. You always get a boost in rpms when the AC is ON. As for the idle drop, did you try to pull any codes? Btw, im in Winston Salem, if you ever need to chance some settings with iCarly

I may need to run by my indy shop and get the codes checked. Thanks for the offer on the iCarly - I may take you up on that!! :thumbup:

^ AC cycles on and off all the time, either in the summer for cooling or winter for defrosting/dehumidifying...

Same Problem on mine before I had the issue with the coil packs and vanos cylinder exhaust side.

I don't think that's it...

Was it caused by the coil packs and/or the vanos cylinder???

I replaced the coil packs and the vanos later. The issue was still there after the coil packs were replaced. So It leads me to believe the vanos was the culprit as its never happened again. I think I have a vacuum leak somewhere. (Idle fluctuations after a warm startup/running errands)

^ Oddly enough my check engine light came on this morning. Ran by my Indy Mechanic and it appears to be an O2 Sensor...I wonder if this has anything to do with the idle issue.

This issue seem to be getting worse - took a very long road trip to drop one of my kids off at summer camp on Saturday/Sunday. While driving at highway speeds everything is just fine however when coming to a stop and idling I'm getting these idle fluctuations more frequently and closer together. Yesterday morning we stopped at a store after driving for about 2.5 hours and my wife went inside for about 10 minutes. I stayed in the car and let it idle. The outside temperature was about 74 degrees and there were no idle dips/fluctuations. Yesterday afternoon when the temperature was in the 80s and up it was doing this quite a lot. I've had the codes read several times and it's not throwing anything.

Something similar happened to me, it would feel like the car is getting a chill, brief shudder while in drive with my foot on the brakes. The dealer first said it was a fouled plug, second time they said it was a bad coil, the last time they said it was the transfer case and swapped it out. So far about 3 weeks in and no shudder, gas mileage is a bit better now as we'll.

The SA at the deal and my Indy Shop said to start off by replacing the spark plugs and the coil packs. Ordered these yesterday from Amazon - all together it was $195 and change for these (NGK Plugs and Bosch Coil Packs).

Additional info: the car is in drive or reverse when this happens and it doesn't do it until it has gotten up to operating temperature.

...pointing more toward the AC cycling?
And I'd love to find the 74 deg spot you are talking about. It's freaking awful hot & muggy here lately.

I've ruled out the AC cycling - I can feel that and know it's normal. I replaced all 6 spark plugs and ignition coil packs today. Unfortunately I haven't been able to driver far enough yet to determine if this has fixed the idle dip.

The 74 degrees was actually north of New Bern near Grantsboro and Arapahoe, NC.

Update: I probably drove 75 miles today - interstate, city, stop and go with traffic. It didn't give me the idle dip at all and the engine is running much much smoother. I'm guessing it was a spark plug.

Arby -

I'm having the same issue with my MY08 X5 3.0si. I've changed the valve cover gaskets and the spark plugs but the idle dip is still occurring when car is in Drive and foot on the brake. Was curious if changing the coil packs fixed the problem. Thanks.

My 07 3.0si is doing the exact same thing. I may need to swap out the plugs and coil packs.

I ended replacing the coil packs and this seem to have fixed the idle dip problem. It's been 500 miles and still no issue.