1994 Ford Explorer 1994 Ford explorer mass AIR FLOW sensor

Is the knocking from a bearing or is it more like valve ping? Also, are you sure the new sensor is bad? It doesn't sound right that a sensor would keep going bad.

Let me know.

Joe

The noise is from valve knocking.
This has happened in the past. The last time I replaced the sensor unit was about a year ago. It is the same conditions, going up hill usually in 2nd or 3rd gear (automatic trans), loss of power, high fuel consumption. . My question is, is there a way to clean/ repair the sensor unit/ wire so that another sensor unit doesn't have to be bought? I have opened one a while back and it is circuitry inside. I also change the air filter regularly.
Thank you Joe very much for your response,
Regen Moore

Based on your description, I really question if that is the problem. These vehicles have what is called a knock sensor. Its purpose is to adjust the ignition timing to the point right before the valves start pinging. The goal is to run the timing as far advanced as possible for optium performance, power, and fuel economy. The sensor is located under hood, center of upper engine area. It's mounted between valve cover and intake manifold. Here is a picture of it:

My concern is without an engine trouble code, this is a guess. As far as the MAF, the only thing you can do is clean it. They actually make a special cleaner for it. However, there are no serviceable parts in it. Let me know what you think about my theory. Joe