Cleaning of the MAF sensor
We have been asked often by drivers, whose air flow sensor failed and who are wondering, if there are other ways than replacing the part. Many forums describe ways to clean their defective air flow meter with brake cleaner or air flow sensor cleaners to make it work again.
But why should the cleaning of the air mass meter work at all?
The reason why the airflow sensor does not work any more, is usually because the sensor inside, that measures the air flow, gets dirty.
The dirt mostly consists of small dust and oil particles which settle on the air flow sensor and thus slowly limit its measuring ability. This is noticeable by a slow loss of performance.
In the older days the MAF had hot wire sensors. You can actually see them when you look inside our old MAF. You can read more about in our blog about the different MAF generations.
Using a cleaning spray like the one on the left side, would help to remove dirt particles and oil from the wires. And if you were lucky, it would work again.
Can air flow cleaner clean Hot Film Sensors?
In the late 80ties Bosch changed the hot wire technology to a hot film technology. Those new HFM (Hot film meters) have a precise and sensitive measuring technology that is not designed for cleaning. Using air flow cleaner would not work, but rather damage the sensitive hot film inside.
This video below shows very nicely how the air mass sensor works exactly.
Thanks for the video, Auto Mate Training.
Conclusion: The appearance of symptoms of a dirty air flow meter is usually the beginning of the end, because even if the actual cleaning process is successful, it is not very likely that all dirt particles will be removed and it will not take long before the MAF starts to cause problems again.
In our shop you can find a wide selection of air flow meters at reasonable prices. Find the correct part for your BMW, Mercedes-Benz, Opel or Porsche here: https://maf-shop.com