Replacing The Fuel Filter In Your Bmw E36: Step-By-Step Guide

Replacing the fuel filter on a BMW E36 is a basic maintenance project that should be performed roughly once a year or every 10,000 miles. This is because, with today's fuels, there is always a chance that gas stations have problems with dirt or grime in the gasoline that can clog your tank.

The process of replacing the fuel filter on a BMW E36 is not overly complicated but does require a number of tools, parts, and safety precautions.

Tools and Parts:

- Floor jack and two jack stands

- Safety glasses

- Rubber gloves

- Paper towels

- Drip pan

- Wheel chocks for back wheels

- Flat-blade screwdriver

- Duct tape

- Large C-clamp or Vice-Grips

- Small crescent wrench

- Fire extinguisher

- Fan

Process:

1. Drive the car until the gas tank is almost empty. This will minimize problems if something goes wrong.

2. Jack up the car. It is recommended to only jack up the front of the car, leaving the rear on the ground. This will minimize any fuel flowing forward to the front of the car from the tank.

3. Identify and remove the fuel pump fuse. On some E36 cars, this may be fuse #9 or #18.

4. Depressurize the fuel system by cranking the engine a few times.

5. Identify and remove the fuel filter cover using an 8mm or 5/16 socket.

6. Put on safety gloves and eye protection.

7. Loosen the hose clamps holding the fuel lines onto the fuel filter and push the lines off each nipple using a screwdriver. There will be some fuel spillage at this stage.

8. Remove the fuel filter from its mounting bracket. On early 4 and 6 cylinder cars, this will involve removing a bolt at the bottom of the fuel filter bracket. On later model cars, there is a protective cover over the fuel filter that must first be removed.

9. Install the new filter, ensuring the arrow on the filter is pointing towards the engine.

10. Slide the fuel lines back onto the new filter and tighten the hose clamps.

11. Reinstall the protective cover over the fuel filter (if applicable).

12. Remove the clamps from the fuel lines and add approximately one gallon of fuel to the tank.

13. Check for leaks under the car and clean up any fuel spillage.

14. Reconnect the battery.

15. Start the engine. It may take a few turns of the key to get the car started as you have introduced air into the fuel lines.

Please note that this is a basic outline of the process and you should refer to the sources below for more detailed, step-by-step guides.

Disconnect the battery and remove the fuel pump fuse to depressurise the fuel system

Disconnecting the battery and removing the fuel pump fuse is an important step in depressurising the fuel system. This is a safety precaution to avoid spraying fuel everywhere when you remove the fuel hoses from the filter.

To do this, first, disconnect the battery. Trust me, you don't want to accidentally short circuit the fuel pump while working around fuel or fuel vapours. Fires can start if the battery is not disconnected.

Next, locate the fuel pump fuse. Open the hood, remove the fuse box cover, and identify the fuel pump fuse. On some models, it is fuse #18.

Now, start the engine, walk around to the fuse box, and pull the fuel pump fuse. You should notice an almost immediate change in the character of the idle before the engine dies completely in a few seconds due to insufficient fuel pressure.

Remove the cover and undo the clamps to access the fuel filter

To remove the cover and undo the clamps to access the fuel filter, you will need to follow these steps:

Step 1: Prepare your tools and safety equipment

Before you begin, ensure you have the necessary tools and safety equipment. You will need a flat-blade screwdriver, safety goggles, and gloves. It is also recommended to have a fire extinguisher nearby as a precaution.

Step 2: Locate the fuel filter

The fuel filter is located underneath the car, adjacent to the frame rail, under the driver's footwell. It is protected by a metal cover, which needs to be removed.

Step 3: Remove the cover

The cover is secured by four fasteners, which can be removed using an 8mm or 5/16" socket. Be patient when removing the front nut, as it has limited access for a ratchet.

Step 4: Depressurize the fuel system

Before removing the fuel hoses, it is crucial to depressurize the fuel system. Start by locating the fuel pump fuse in the fuse box and removing it. This will cause the engine to die within a few seconds as the fuel pressure drops.

Step 5: Loosen the hose clamps

Loosen the hose clamps on the fuel lines connected to the fuel filter. Be prepared for some fuel spillage, as there will still be residual fuel in the filter and lines.

Step 6: Remove the fuel hoses

Use a screwdriver to gently push the hoses off the fuel filter nipples. You may need to rotate the hoses or use an open-end wrench to pry them off. Be cautious, as the fuel is under pressure and will spray out.

Step 7: Unclamp and remove the fuel filter

The fuel filter is held in place by a metal clamp and a 10mm nut. Remove the nut and loosen the clamp to slide the filter out.

Loosen the hose clamps and remove the fuel lines from the filter

The first step is to ensure you have the right tools for the job. You will need a floor jack and two jack stands, safety glasses, rubber gloves, paper towels, a drip pan, wheel chocks for the back wheels, a flat-blade screwdriver, duct tape, a large C-clamp or Vice-Grips, a small crescent wrench, a fire extinguisher, and a fan in a well-ventilated area (outside of the garage is preferable).

Before you begin, depressurise the fuel system. Start the engine, walk around to the fuse box, and pull the fuel pump fuse. You should notice an almost immediate change in the character of the idle before the engine dies completely in a few seconds due to insufficient fuel pressure.

Now, crawl underneath the car. The fuel filter is generally in the same location for all of the cars—located on the left side of the car, somewhat underneath the engine.

Loosen the hose clamps on the lines going to the fuel filter and slowly work the lines off. I recommend clamping the fuel line before disconnecting it as this will minimise the amount of fuel that will leak out. However, you have to be very careful clamping the line, otherwise, you may damage it. A large C-clamp works well, or you can use Vice-Grips, but only if you cover the jaws with several layers of duct tape. It's okay to squeeze the line closed tight, but you don't want to score, rip, or crack it with your clamping tools.

With both the inlet and the outlet to the fuel filter clamped, release the hose clamps on either side. Have a small pail or bucket handy to catch the excess fuel when you release the line. Sometimes the line will slip off, but sometimes it will require some coaxing. I recommend using a small crescent wrench that fits nicely around the fuel pump inlet, but is too small to fit around the fuel line. Wedge the wrench against the filter housing, and you should be able to pry off any stubborn fuel line. If all else fails, and you simply cannot pull the line off of the filter, then make a small 1/4" cut along the length of the line and try again. Continue making cuts until you can remove the line. This will minimise the amount of line that you will have to cut in order to get the filter off.

Install the new filter, ensuring the arrow is pointing towards the engine

Now that you have removed the old fuel filter, you can install the new one. First, make sure that the arrow on the filter is pointing towards the engine. This indicates the direction of the fuel flow. Slide the new filter into the clamp and put the 10mm retaining nut back on the stud. Spin it on a few threads so it's secure but do not tighten it down yet.

Next, attach the fuel hoses. Press the hoses onto the nipples and fasten the hose clamps snugly. You may find it easier to install the shorter hose first as the longer hose is more flexible. Then fasten the filter clamp to tighten the filter down to the car.

Now, restore the wiring and fuel lines. Return the adjacent fuel lines and wiring to their original locations, using a couple of cable ties as necessary.

Finally, mark the filter with the in-service data. Using a permanent marker, label the filter with the current date and mileage for future reference.

Reattach the fuel lines and check for leaks

Now that you have the new filter in place, it's time to reattach the fuel lines. Slide the fuel lines back onto the ends of the filter and tighten the hose clamps. Make sure the clamps are tight, but not too tight, as you don't want to strip them.

With the new filter installed, you can now re-install the protective cover over the fuel filter.

Now, remove the vise grips or locking pliers from the fuel lines, and add approximately a gallon of fuel to the tank. Check for leaks under the car. If you detect any, fix the problem immediately.

Wash your hands to get off all the residual fuel and re-connect the battery.

Now you are ready to start the car. Keep in mind that since you replaced the filter, you introduced air into the fuel lines. It may take a few turns of the key to get the car started, so don't be alarmed if the car suddenly dies a second after starting. After one or two times, the car should start.

While the engine is running, examine the fuel filter installation for any leaks and tighten the clamps as necessary.

Frequently asked questions