BMW / MINI Cooer Fuel Filters – Lifetime?

We seem to be coming across a set of items that used to be normal service items on cars, that are now deemed “lifetime” by the manufacturer. However, they don’t seem to be holding up to that claim. If they were just not holding up to the claim, that would be one concern, but what we are seeing as a trend is that these “lifetime” items are causing other more significant issues. Here is another one that is drawing concern from us.

MINI Cooper, and BMW, now claim that the fuel filter is a lifetime device, and does not need to be serviced or replaced during the life of the vehicle. There are many thoughts on why this might be. The fuel filter (on pre-2000 year BMWs) used to be external, in line, between the fuel tank and the engine. This made service and access relatively simple. However, now, the fuel filter, has been moved from external to internal, in the fuel tank. This started with most new BMWs after 2000, and all MINI Coopers. Service is not straightforward at all when the fuel filter is located in the fuel tank, and even access to examine it is near impossible. What used to be a simple service job that took less than 30 minutes, now, if needed, takes well over 2 hours and a high level of expertise.

(The picture below is of a MINI Cooper fuel filter assembly. The fuel filter is located in the fuel tank, which is under the rear seat. The fuel filter assembly is on the right side (passenger) of the car. Once you remove the rear seat cushion, the fuel tank cover, you will see the item as shown below. You then remove the metal retaining ring, and you can then play with the fuel filter assembly. Remove the fuel lines, then remove the clips to the assembly cover, and you can access the fuel filter).

While we can hazard lots of guesses as to what changed to make a unit that was a service item all of a sudden not become a service item, but most defy logic. The engine didn’t change. The low pressure fuel pump system didn’t change. The fuel didn’t change. The cleanliness of the fuel didn’t change. How you fill your car with fuel didn’t change. So, why did it no longer become necessary to change the fuel filter due to the dirt and contaminants in the fuel to keep your car running right When it has now become more critical (due to the evolution of direct injected engines) to ensure proper fuel flow, why would you not want to service the fuel filter?

(Picture below is a fuel filter from a 2005 MINI Cooper S, and the new replacement filter on the right). This clogged fuel filter caused the failure of the fuel pump on our customers 2005 MINI Cooper S.

Again, if that were all that it was, is a concern on what or why things changed, no big deal. But, what we are seeing is that the fuel filters are still becoming dirty, and clogged. And, the clogged fuel filter is killing the fuel pump. Now a simple fuel filter service, that can not be done, has gone and caused the failure of the fuel system. This means your car won’t run. It could stop when driving. It could run today, but not start and run tomorrow. That could be a safety issue. Certainly could inconvenience you just when you needed to rush to work, and your car decides to not work that day due to the failed fuel pump. But, that’s not all, the simple fuel filter (lifetime) has now caused you to have a >$1,000 service repair bill.

We used to have the guidance that it was wise to replace the fuel filter at about 60k miles. We would have you consider still doing this service and not wait till the clogged fuel filter kills your fuel pump (or some of the other secondary effects, like running lean or low fuel pressure and misfires).

BRracing – keeping car running at its full potential.