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MAF (Mass Air Flow) Sensor Clean 130 TDCI
Contents
MAF (Mass Air Flow) Sensor Clean - 2004 130 TDCi Euro 4
Disclaimer
Disclaimer: As we live in a litigious world I have to make it clear that no guarantee or warranties are expressed or implied, you follow this guide entirely at your own risk. If you, your car, or any 3rd party is damaged as a consequence of following this guide that is not my responsibility. Hope that is clear!
Introduction
MAF (Mass Air Flow sensor) relays information to the ECU/PCM regarding the amount of air that is being drawn into the engine. With this information, the PCM varies the fuel needed to keep the car running as it should.
Certainly on earlier fords (not sure about the Mk3 Mondeo - but most likely!), the information from the MAF also had an influence on the automatic gearbox and its function.
The Mondeo uses a 'hot wire' MAF sensor - basically, a wire is heated to a set temperature, and the MAF electronics measures the electrical current needed to maintain that temperature... so, the more air going through, the more there is a cooling effect on the wire thus the more electrical power is needed to maintain the wire at its temperature...
Although the MAF is located on the 'clean' side of the air filter pipework, microscopic particles will get drawn through the air filter into the inlet tract of the engine, over time there will be a build up of particles that have burnt onto the MAF hot wire. This leads to a condition where more electrical current is needed to heat the wire in the first place, but this is due to the muck burnt onto the wire and not because of increased airflow, thus inaccurate information is sent to the PCM.
When the MAF gets dirty, it will be sending inaccurate information to the PCM, leading to driveability issues. (hesitation.. poor 'pick up', etc)
Note that a dirty MAF wont usually generate a 'Engine Management' light on the dashboard, as the readings a dirty MAF is relaying to the PCM arent out of its operating range... it is just inacurate readings.
As my car was experiencing some low revs drivablilty issues, I decided to clean out the MAF sensor.
The photo sequence that follows shows the work involved on a 2004 Ford Mondeo 130 TDCi ‘Euro4’, though I am sure other models will be similar.
The text and photos were done by Dave Yardy (daveyardy@hotmail.com) and this is the 'version 1'. The pictures are quite big currently... but will resize them at some point in the future...
Parts and Tools Needed
The work involved is simple and should well be in the capabilities of the home mechanic, the car doesn’t need to be lifted and the work is all done at the front of the car.
You need a T20 Torx srewdriver to remove the two screws that hold the MAF in the inlet duct.
A handful of cotton buds.
Paper Towel
Some Electrical Contact cleaner / Carburettor Cleaner / Isopropyl alcohol.
Locating and removing the MAF
Disconnecting the MAF will generate a Fault code/trigger a EMF light, so before starting.. its worth ensuring that the ignition is 'off', You may wish to disconnect the battery.
The sensor is located on the top of the air inlet trunking... just infront of the brake fluid reservoir
This picture shows the MAF sensor that is to be removed (inside the red box):
- Unplug the electrical connector
- Undo the two torx headedscrews holding the sensor into the duct.
- Pull the sensor up and take it to the workbench..
- Note that the sensor is *very delicate* dont drop it! - New ones are circa £100!
Cleaning the MAF