by Jobe Tichy

In the early production years of the 318I, the fuel filter was located in the engine bay. If you have ever referenced the fuel filter replacement in the Bentley repair manual, you will see it tells you it is under the car in front of the left rear wheel. On my '84 it was not. For some reason BMW located the fuel filter on the left side of the engine bay, underneath the master cylinder in a vertical direction. This is not only a very inconvenient location; it is also a dangerous location. It is inconvenient because you have to get it out from under the car and it is dangerous because it is next to a live hot wire going to the starter and any current from which could start a fire. This is a job I did with help because work needs to be done both above and under the car. Also, if you don't like working around gas, have a fire extinguisher handy just in case. Also, use eye protection when you are under the car. You can try and use rubber gloves, but the gas (depending on how much you spill) eats right through them. To replace the fuel filter-

• Remove fuse #11 (15A) and start the car.  Let it run until it dies. This will depressurize the fuel system                          (from Haynes Manual - thanks Brian Ruiz!)
• DISCONNECT THE NEG. BATTERY LEAD!!!! DO IT NOW!
• Put the front of the car on jack stands for ease of work. You will be able to maneuver better.
• Loosen the hose clamps that hold the filter into place and push the filter down.
• With the filter loose and hanging down, from under the car loosen the hose clamps that are connected to the filter.
• If your new filter is a Bosch, it should come with some end caps on the new filter. Because fuel will be coming out of the filter when the hoses are disconnected, keep the caps handy so you can cut off the fuel flow soon, for a clean job.
• Remove the top hose and have a helper from above the car clamp the flow of the top hose with their thumb. While the other person is under the car with the filter, place one of the end caps over the filter to stop the pressurized flow of fuel. Using the caps is very convenient to keep gas from leaking.
• Now, remove the old filter; clamp the hose with your thumb to prevent gas from leaking. With a cap on the exit end of the new fuel filter, put the lead hose onto the new filter and tighten it down. MAKE SURE THE FLOW OF FUEL FOLLOWS THE ARROW ON THE FILTER!
• Reinstall the filter with the hose clamps back up under the master cylinder.
• Remove the end cap and reattach the end hose and tighten down.
• Wait for any gas to evaporate before starting.

 

 
 





 
 


RESULT- Changing the fuel filter is a great cheap fix for a high idle and bad fuel economy. The car should start easier too. With the new filter, the car idles perfect.

-Jobe Tichy

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