Welcome to Tech Talk, where our resident BMW tech Nick Owen answers all your pressing BMW technical questions, frustrations, and issues. Have a question for Nick? Email him at techtalk@roundel.org. Let’s get into it.
M235i Codes
I’ve had an interesting experience with my wife’s M235i. She experienced an engine light a few months ago. There were no adverse symptoms, so I went in, looked at the code, and cleared it. I don’t recall the exact number, but it was related to “catalyst efficiency.” It popped up again last week.
I intended to go back and check it again, but we took a drive and I noticed it was out! Now she tends to just amble around town generally. When I drive it, it’s in a more spirited manner, shall we say. Is that related? Does she just not run it hard enough and it needs an occasional Italian tune-up?
John Ehrhart
I think you should have it looked at. If there is a defective catalytic converter, the dealership might have it replaced under federal emissions warranty, but I would let them make the determination.
K&N Air Filter Worth It?
My 1986 535i is running great. The parasitic drain was a nightmare to fix. Is a K&N air filter worth the money over the paper filter usually in these cars?
Chip
My take on K&N air filters is that they have their place if you’re the kind of person who does not mind servicing it every 10,000 miles or so. A “service” is basically just shaking it out and maybe hitting it with pressurized water to help it dry. But I am also not a fan of their “cleaning oil” they sell. which is supposed to clean the K&N filter due to the material and design of the filter. I never understood this because the only thing that should be going into the engine is air (and fuel) so oil from a K&N cleaner just makes me think it will contaminate the MAF sensor. As silly as it may seem, the paper filters get the job done just fine.
2022 X5 transfer case “lifetime” fluid ruining xfer cases
I write to ask for coverage of BMW’s “lifetime” fluid in transfer cases. There is sadly no drain plug which any mechanically-minded person knows is a bozo-no-no.
Perhaps you’ve covered this issue in Roundel. I apologize if I missed it. It is at the heart of a current class-action suit and I own one of the affected vehicles, a 2022 X5 M50i.
I can offer more details of my experience if you’re interested. I would love some additional press to highlight the stupidity of this concept.
Dale Knoop
Overland Park, KS
I wish I could provide a solid insight as to why the transfer case does not have a drain plug (We would use a vacuum device to suck the old fluid out) or why the service interval is not recommended due to “lifetime” fluid. (Ironically, the transfer case fluid has a service interval built into the VTG module that stores a fault when it time outs, but you have to scan for it).
The only real thing I can offer from my years at the dealership is that the Germans do things their way. Unfortunately, that way is not always best, which is why we have had several recalls and class action suits over the last two decades or so. E46 subframe, N54 fuel pump, N63 valve stem seals, now xDrive transfer cases. It’s highly unfortunate that items like this are failing at a rate far too high, requiring a class action.
Considering there is a class action in place, my gut says they will add an extended coverage warranty to the current transfer case units that have not yet failed while replacing those that are currently failing and reimbursing those who paid to have them replaced. The issues with a class action are that they do have to fix all the affected models, but they will not have enough new transfer case units ready to go. So, they will have to stagger the release of new transfer case units to the cars that need them now. They know they have a problem, but they also know that if they do not roll out the fix correctly, it can catastrophically damage the financial stability of the brand.
