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Originally Posted by flicks28
Has anyone been able to determine the approx. build dates on the cars that are having problems?? I dont know what the date is on mine yet, but will find out. This is important for two reasons.
If the build dates are fairly close together (I'd say about 6-8 months since the first cars to have this problem in the field would probably take a few months and then it will not be seen as a bigger problem until a few months after that) it could be that the supplier to BMW was running parts slightly out of spec for an extened period of time. This could be that when the lifters, camshaft, etc was designed, the tolerances could have been too large. The problem could then be corrected by tighening the tolerances. Or, the parts were being run in production without the operator performing the correct 1st piece checks, or quality checks during the parts run period and a large batch of these hitting the field. I dont know if BMW uses a kanban production system, but this system is the best way to cut down on large production runs of out of spec parts.
Or, the larger and more serious problem, is that this is a design flaw and can only be corrected by modifying the engine or another important part. I would be curious if there is a modification to the engine size, shape, etc in the mid-year 2007's compared to model year 2006.
With my previous experience with Japanese auto companies, if we happened to receive a field claim (car that is out on the road that reports a problem) we would be able to determine the reason of that problem with 2 weeks, if not earlier. I would have to believe that BMW has a good idea what is wrong by now. We would have to always determine a way to correct the problem in the cars already sold, but then we would have to develop a solution to future cars to be built. The cars already on the road needing servicing were more or less patch jobs (quality patch jobs) but a different fix from what future vehicles would receive.
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These are good questions. I don't think there are definite answers (BMW still researching the problem, working on a fix or just keeping the answers from public) but a quick summary so far: there are cases were cam, lifters and rockers were replaced and problem went way for good, there are cases as well were even when all parts were replaced noise came back, than again there is a theory that magnesium is very hard to work with and some engines have flaws, than there is a theory that there is a design flaw with oil pathways. One thing for certain if you hear lifters ticking and let them to continue problem gets worse. So, you got to get it fixed and until then use whatever method (spirited driving, engine braking and etc) to keep liters lubricated.