I have a 1997 F150 XL 4.2L. 15 months ago I started having problems. During normal driving, my truck would lurch as if it was about to shut off so I took it in to my dealership and they replaced the Cam position sensor. Well Now it is doing it again. Could anyone tell me What is causing these to go bad so early? Any suggestion would be greatly appreciated!

 

Position sensors are vital to the modern engine management computer and difficult to manufacture well. A sensor that does not rely on physical contact between a sensor and a resistor lasts longer. Non-contact sensors usually involve electromagnetic fields and a repeated signal from a metal object passing through the field. I would guess that the camshaft sensor is non-contact, as it is a rotating shaft. The electromagnetic signal could be degraded by an oil leak in the sensor vicinity.

As an emissions-control device, your sensors should be covered by a long term warranty.

 

1995 and newer car & light truck emissions components are only covered for 2 years or 24K miles under federal law, with the exception of the PCM, OBD device (integral with the PCM on Fords) and catalytic convertor(s), which are covered for 8 years/80K miles.

Manufacturer's 3/36 bumper to bumper warranty exceeds federal emissions warranty.

See the following link for emissions warranty details:

[link:www.epa.gov/otaq/consumer/warr95fs.txt|EPA website]

Back to the original question....Are you sure the CMP sensor is actually bad again, or are you just assuming it's bad because the symptoms are the same as they were last time?

 

I have replaced the sensor and have no problems to date. But... I am holding for it has only been a few days. Thanks for your replys