Following on from my earlier post about excessive oil consumption in my 2005 X5 4.8is, the problem have morphed into something worse - smoke from the tailpipe during idle. I've asked around at some independent shops, and their initial thought was that a ring or gasket of some sort may be the culprit. However, after 5 days at my local dealer here in Florida, they could not identify any of the normal issues that lead to oil smoke. And, for some reason, they also were unable to re-create the smoking situation while they had the car. (interesting) Of course, when my wife goes to pick up the vehicle from the dealer, it starts plumming smoke. After another day or two with the car, their hypothesis is that oil is somehow bleeding into the valves, and to repair it would be "woefully expensive" (their words). Estimate $6k!!!! Anyway, I wanted to know if any of you have had any similar problems? Or, do you think there could be another explanation for the smoke? Also, if you have heard of oil bleeding into the valves, do you think its worth trying to repair it at an independent engine specialist shop or do you think I should cut my losses? The X still runs very strong, and the smoking only occurs during prolonged idling after a day of around time driving. Thoughts?
After you've had the dealer look at it for that long, I'd presume they would have ruled out the OSV (oil separator valve) or this: http://www.bimmerboard.com/forums/posts/11919 (I'm assuming your engine is essentially a larger, tweaked version of the 4.0l v8's BMW introduced in the mid-90's and might be likely to suffer many of the same issues. I guess worst case scenario is you have a cracked head (or engine block - but, that would seem highly unlikely), or bad head gasket. After that, obviously oil is leaking somewhere, it's a matter of finding it. Taking things apart and putting them back on that engine is time-consuming (because there's a lot of stuff), and thus, expensive, particularly at dealer rates. Unfortunately, it's like authorizing exploratory surgery - just start taking stuff apart with the hope, but no guarantee, of finding anything. It would appear, from what your saying, that the oil that's leaking blows through the engine at higher rpm highway driving, but builds up enough with low-rpm street driving to not get blown out, and thus smoke. You might want to search bimmerforums.com, bimmerboard.com, & bimmerfest.com and see what you find. The earlier 4.0l v8's seem to need a slew of work around 100k or so, if one wants a relatively issue/worry-free next 100k. Yours may be no different, but I don't know, I'm not up on the specifics of the later-gen v8's.
