Question about 2002 Mercury Grand Marquis
A knock sensor is basically a resistor and a spring, and what it does is it reduces valve ping. Valve ping is when the fuel is not properly burned and tries to explode before the valve is fully closed and it will make a pinging noise when under load or at higher RPM. If the sensor is bad it can cause detonation, detonation is when the fuel explodes before the valve is closed and can cause a cracked, or exploded piston, bent valves etc. Your problem does not sound like that of a bad knock sensor, predominantly you will only hear the "ping" under load and not at idle and if it was bad your check engine light should be on. this sounds more like a rod knock. change the oil again and use only AMSOIL and an amsoil filter, amsoil is proven to last longer than any other oil, 600,000 miles without a change, or a filter change.
Posted on Feb 05, 2010
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Posted on Jan 02, 2017
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