BMW Repair Questions? Ask a Mechanic for Answers ASAP
Thank you for using JA. I'm Baz, one of the automotive experts, I try to be available in the afternoon on weekdays and in the evenings on the weekend. I apologise if I do not respond to your question promptly, I can assure you that I will respond as soon as I can. Thank you
Have you taken the car to an independant garage for a second opinion (not a main dealer)? I wouldn't blindly go off what a main dealer says. There are many independant BMW specialists about.
I don't understand what "internal fault" is so, I can't comment on the safety but I wouldn't recommend going on a long journey. Is the car affected by this fault when driving? Are there any noises? Has it lost power?
I think you should wait until the independant garage connects their diagnostic scanner to check the fault codes stored. Main dealers never tell you the fault codes because the customer may go elsewhere and get it repaired. "internal fault" could be a wiring issue or a control module failed and they can be repaired/replaced using online repair services.
Carbon build only happens in the engine + components, not gearbox. Is your gearbox auto/manual?
I believe you're referring to the DPF. The carbon only affects engine cylinders, valves, air intake components, turbo, exhaust. The gearbox has nothing to do with it.
If the gearbox has actually failed, it will be a mechanical failure of the components inside which are inside a sealed unit. You need more information than "internal fault" and I highly doubt that the BMW diagnostic scanner just stated "internal fault", each fault has it's own fault code/related code which is stored when a fault occurs.
No, it's not normal. A transmission should be for the life of the car. A second opinion is very important at this time, main dealers love changing parts so, I wouldn't trust them so quickly.
Welcome :) i'll be available to help, just message back on here.