Replacing Your MINI or BMW Fuel Filter
In previous issues of Fast Times, we have recommended periodic replacement of the fuel filter. (See the Winter 2008 issue for Otto’s Ultimate Preventative Maintenance Schedule.) This has generated a common question for Otto: “Where is my fuel filter?” In this article we will show the locations for the fuel filters on most models and describe the general procedure for replacing the filter. NOTE: doing this procedure on many BMWs and MINIs requires that you lift either one end or one side of the vehicle for access. See safe jacking and supporting procedures.
Various locations of fuel filters.
1. Under driver’s side floor, inside of frame rail covered by splash panel:
3 series 92 thru 05 (except 92 convertible), Z3, 5 series 97 thru 03.
2. Under driver’s side rocker panel, at rear:
Most 3 series 84 thru 91, 92 convertible. (NOTE: see #3 below.).
3. Engine compartment, in front of firewall on frame rail:
Some early 3 series 84 thru 91.
4. Above right-rear axle:
3 series thru 83, 5 series thru 96, 6 series thru 89, 7 series thru 94.
5. Under passenger’s side floor, inside of frame rail:
7 series 95 thru 01.
6. Under driver’s side seat floor, in front of fuel tank:
X5 thru 06.
NOTE: These following BMWs have the fuel filter mounted in the fuel tank:
3 series 06 on, 5 series 04 on, 6 series 04 on, 7 series 02 on, X5 07 on, X3, Z4, MINI.
General replacement instructions.
What follows here are steps that apply to all fuel filter replacements. Model-specific instructions can be found in the appropriate Bentley repair manual.
NOTE: Before beginning, make sure you are wearing safety glasses and fuel-resistant gloves!
Release the pressure in the fuel lines as follows:
• Start the engine. While the engine is running, remove the fuel pump relay or
fuse. (For model-specific instructions, refer to the applicable Bentley manual.)
• Let engine continue to run until it dies from lack of fuel. (There will still be
fuel in the system, but it will not be under operating pressure.)
• Disconnect the negative battery cable and remove splash shield (if applicable.)
• Close the inlet fuel hose (between the pump and the filter) using a fuel line clamp or a pliers-style clamping tool (available at most auto parts stores). If this is not convenient or not possible due to the fuel line configuration, you’ll need a suitable container to collect residual fuel as it drains.
Before removing the old filter, note the orientation of the flow arrow on the filter and install the new filter with the arrow pointing in the same direction.
When disconnecting the fuel hoses from the filter, have a large rag and a drip pan to catch any fuel that drains.
Be prepared with new hose clamps or, if applicable, sealing washers for the hose connections.
Inspect the fuel hoses for deteriorated ends, cracks in the outer sheathing or other signs of wear that show potential for leaking. Replace any hoses that show signs of deterioration or cracking.
Inspect the rubber isolator mounts for the filter/pump mounting bracket (if applicable). Replace the mounts if they are deteriorated or broken.
Once the new filter is installed, prior to replacing any splash shields, replace the fuel pump relay or fuse, start the engine and inspect for leaks at the filter connections.
Follow along as we show the basic steps for fuel filter replacement on a 2001 Z3.