496 Mag Crank Sensor

[dyoung]

Any ideas what would cause cra

Any ideas what would cause crankshaft sensors on a 496 MAG to keep failing? Replaced 2 in the last two weeks. Engine has less than 68 hours on it.

 

[mistahays]

"Is it touching the crank? Cr

"Is it touching the crank? Crank sensors, like wheel speed sensors on a car with antilock brakes, just generate a magnetic square wave that varies in frequency with speed. When they get full of crud/metal dust/fragments... the signal gets boogered up. I'm sure there is a much more nautical explanation but there you have mine.

Hays"

 

[dyoung]

"When the ohms is checked it s

"When the ohms is checked it shows that the sensor is bad, almost as if something has shorted out. I'm not sure as to what might have caused this. I don't think it is touching the crank, because it runs fine for about 45 minutes before going bad."

 

[guyjg]

Check your grounds. Clean all

Check your grounds. Clean all the debris and dirt from the area as MistaHayes stated about dirt being a problem. Take a magnifying glass and look very closely at the sensor wire plug pins; may be corroded. Perform a ohm test on the sensor wire with both ends disconnected; it may be corroded internally or you just need a new sensor wire pigtail.

 

[dyoung]

I'll check that.....Thanks

I'll check that.....Thanks Guy