Any wisdom/recommendations from you experts would be so appreciated. I've had issues with the rough idle for about 3-4 months now. I spent a couple of hours reading everything I could find on the issue. As far as I can tell, there is a cold start idle issue and and warm start. It seems that mine falls in the category of the warm start.....which from what I've seen on these forums is about 25% of the time. Here's what my car is/has been doing:
1. Turn the car on in the morning and as it warms up, it does something weird after a couple of min, idle comes down to 500 rpm...and yes, I get the increased rpm/surge when I put it in reverse. I can live with that.
2. I have NO ISSUE when the A/C is off. But once the compressor kicks in, the idle goes to 700 rpm and then it begins to wildly flutter up/down. I've seen it as high as 900 and as low as 400 rpm.
3. This issue occurs in Drive only - if I put it in Neutral or Park it idles normal.
4. Have had "Service Eng Soon" light come one a couple of times..with the Increased Emissions message. The first time I took it in to the dealership and they replaced the crankcase valves. I picked it up and was back within 15 min...Light came back on. It ran much smoother after that...but the idle issue came back the next day. I can't remember what they did then but I guess they just cleared the msg??
5. A few days later I get the "Service Eng Soon" light again while sitting at a light with the A/C on. Drove it for about 10 min. Then it idled wildly and I immediately noticed that the "Service Eng Soon" light actually came off or cleared itself. But I was still having the problem. So I went back to the dealership. I left the car on and had the Serv Mgr come sit with me while he watched. He did tell me that light fluttering of the RPM needle is "normal" for these engines (incl. X5 and 745i) but the engine doesnt do what mine was doing. So I leave it again. They check everything and could find nothing else wrong.
6. Serv Mgr calls me and tells me that they are going to try to reprogram the engine overnight (valve lift program?? idk) and they also upgrade the CCC software in iDrive. I mentioned the 25 sec relearning prog and he says: "No, you have to do a computer reprogram for the engine to relearn itself". He tells me they drove it several times that day and could not get it to do the same thing. So I pick it up that evening..running smooth! He also tells me that it may be a bit touchy since its reprogrammed to brand new specs. New software in iDrive and the car is really, really driving well...A/C on and everything.
7. The very next day that evening the rough idle comes back with a vengeance. But I notice the following: the issue is still when the A/C comes on...but when I left during lunch car was fine and I usually keep my A/C temp around 76° F or so (yes, blue bars in iDrive) operating normal. But then in the evening, 90's outside, hot car, A/C acts like normal but then it switches and I can barely get any air. I have to put the thermostat all the way to the left at 60° F and it still not blowing enough. Everytime I come to a stop I have to either endure the idling/sputtering or put it in Neutral. I've been driving like this for about a week now. Everyday is like clock work. Come 5 pm I have to put the A/C on manual so I can get enough air (dont forget I'm in Tx!). Now I got the Service Eng Light-Increased Emissions light again yesterday.
Interesting note: When I dropped off the car the last time at the dealership I printed both SIB's (cold start and warm) and gave them to the Serv Mgr. After I picked up the car he told me that if the reprogramming didnt work that the only alternative is doing the SIB procedure---which he tells me it will be around $2000 or so. I have no warranty, my CPO ran out in Feb 2011. I am really disturbed now because I dont really have ANY confidence or guarantee that the SIB will fix the problem. And besides that...if I want to get rid of the car...who is gonna give me what is worth with this obvious issue?
I do not where to go from here. I'm ready for them to just buy it back...but at what cost? I'm not willing to shell out thousands with no guarantee of a fix. I've really had my fill of this problem.