Meister, some good detailed information in your posts above. One comment would be that BMW can't be said to be changing their recommendations (which implies that the same engine or transmission is under discussion) if in fact the components changed from year to year. Your note shows that different engines have different maintenance recommendations. It isn't all about extending the intervals, it is about optimizing the maintenance cost when considering risks and other factors. If BMW are providing different recommendations for different engines (in the same model year) then that implies to me that the marketing department is not simply saying don't maintain them, but that the engineering department is saying that in this case, with this usage profile, with this engine, do the following.....

For most components, changing the fluid has little downside. For coolant, I would do it every four years, as the only downside I see is the environmental impact of disposal of the used fluid. You aren't going to negatively impact the cooling system. You can get coolant tested, but that is probably more work than reasonable.

The tranmission is the only component that I wouldn't touch, and it is due to the risk, which I have seen the consequences of. I know that I called it slight (Sunny keeps reminding me) but it is still greater than the offsetting benefit in my mind.

If I had a 100,000 mile warranty, and a 100,000 mile fluid change interval recomendation from BMW, I certainly wouldn't give BMW cause to deny warranty (when I fully expect the trans to fail anyway) by touching it. It is very easy to tell if a transmission has been opened.

Yes, it is a thoroughly dead horse, but I suspect some people are still finding out new information.

I'm not even going to bother responding to what you wrote as you're obviously not reading what I have written. From my second post on this subject I clearly said:

"There is the possibility of dislodging sediment but even if that were the case I have seen no evidence to support that dislodged sediment correlates to transmission failure. So while the risk is there I think a transmission failure resulting from it is so rare as to make it a non-issue."

And in my next post on the subject:

"I previously acknowledged the possibility of disloding sediment. However my personal opinion, and it appears it is shared by JCL, is the possibility of it happening is very low. Furthermore should sediment be dislodged I have seen no evidence it will result in a transmission failure. So the chances of dislodging sediment are very low and the chances of dislodged sediment resulting in a transmission failure are very low."

And my next post:

"There you said you felt the chances of dislodging sediment are slight. I agree with this."

And the following post of mine:

"We're in agreement there is a slight risk accumulated sediment can be dislodged."

And my next:

"It is your theory the transmission failed because of the fluid change but you cannot offer anything other than a theory. What is surprising is you continue to say there's a slight chance it could happen. Of which I agree."

And my next:

"Is there a risk? Most certainly."

Given I have repeatedly acknowledged the risk throughout this discussion but you seem to feel I haven't until my last post I see any further discussion with you as futile.

I would like to hear JCL and other's explanation as to why BMW did this.

:thud:

You admit to the risk, then refer to the risk as a non-issue and call it an urban legend over and over multiple times after the fact. You are clearly talking out of both sides of your mouth.

You keep asking for proof, but if someone as heavily involved in the technical side of BMW as Mike Miller doesn't convince you over your mechanic, then I don't know what to tell you. He states he has clearly seen too many of these failure cases. Too many isn't a non-issue or an urban legend to me. It may be to you though.

I feel as if I am wasting my breath on you. Carry on.

Last ditch effort here. From what I have read, they changed the definition of "lifetime" regarding the trans fluid because nobody knew what lifetime meant. Lifetime of the car, the component, the original ownership, etc. They threw a number on it to try and clear up some confusion. I have not heard that it was due to the fluid going bad, trans failures or anything related to maintenance. Pretty sure it had more to do with marketing and customer relations.

No, there's no double talk. There's a risk. However risk does not equal a problem.

Welcome to my conclusion of my discussion with you since you obviously were not listening to what I wrote.

Yeah but they went in the opposite direction with the coolant and you can ask the same question !?

It's a foolish explanation. What he's saying is BMW decided, for marketing purposes, to recommend a proceedure alleged to cause transmission failure.

That explaination comes from Mike Miller. :confused:

We are officially done here sunny.

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Mike Miller's Alternative BMW Maintenance Schedule
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