The mass air flow sensor in your BMW is primarily how your engine computer controls the delivery of fuel to your inline six engine. The BMW 330 MAF sensor is mounted inline with the intake piping and mounted to your airbox. When this sensor starts to go out, or is fouled your engine computer won’t be able to accurately operate your engine. Before you start to test your BMW MAF sensor, you would be well served to understand what this sensor does for your 330i.
The 330 MAF sensor reads the air that’s heading into your engine. It does this using a hot wire sensor that analyzes just how much air is passing through your BMW MAF sensor. Along with the air volume, the 330 MAF sensor also reads the air temperature as well as other vital information. Your BMW engine computer uses this information to properly deliver the right amount of fuel for efficient operation.
Today I’ll be showing you how to service your 330 MAF sensor in a 2001 BMW with the inline six engine. The air box filter for your BMW in this vehicle is rather large and hard to remove, so you’ll need to take extra care when replacing your mass air flow sensor.
To begin you will need to open you hood and loosen the plastic pop rivets that secure your air intake duct. This duct runs through the radiator support and must be removed before you can lift up on the air intake box.
Once you’ve got this duct removed, you can pull forward and take the intake duct out of your airbox. There’s several bolts that run through the intake air box and secured to the chassis of your BMW.
The intake piping is extremely tight here, so you will need to remove these bolts first. Then push the air box back towards the back of your 3 series. Once you have the air box pushed back and freed, you can undo the clamps that connect the back end of your 330 MAF sensor to your intake pipe.
Now that clamp is loosened, you must pull up on the metal pin on the 330 MAF sensor harness.
Once the metal pin is pulled up, you can disconnect the MAF sensor harness, and begin removing the MAF along with the huge BMW 330 air intake box.
Once the 330 MAF sensor and air box have been removed, you can unclip the MAF from the air filter housing. Remove the 330 MAF sensor and install your replacement, make sure to line up the air flow sensor correctly.
Once you’ve got the new 330 MAF sensor installed, reconnect the engine harness. If your BMW 330 check engine light is turned on, you’ll need a OBDII scan tool to erase the trouble code in question.
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