Hi welcom to fixya.
A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark ****** than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.
To replace the knock sensor:
Knock sensor is located on side of engine block screwed into a block
coolant drain, your best access is from underneath the vehicle. Coolant
will run out when you unscrew it so be sure the engine is cool. Just
unplug the wire unscrew the sensor, screw in the new one and plug the
wire back in. Also be sure to top off the radiator if you loose any
coolant.
There are some model yukon engines ( big V 8's) that have the Knock
sensor(s) 2 that are under the intake manafold. the one that goes bad in
those type of enines is the front one. Must remove the intake manifold.
Fig. Right engine compartment view-4.8L, 5.3L, 6.0L and 6.2L
engines (1) Ignition Coil 8 (2) Ignition Coil 6 (3) Ignition Coil 4 (4)
Manifold Absolute Pressure (MAP) Sensor (5) Throttle Body (6) Ignition
Coil 2 (7) Knock Sensor (KS) (8) Crankshaft Position (CKP) Sensor (9)
Engine Oil Level Switch (10) Starter (11) Valve Lifter Oil Manifold
(VLOM) Assembly (12) Engine Oil Pressure Sensor
Fig. Front engine compartment view-4.8L, 5.3L, 6.0L and 6.2L
engines (1) Throttle Body (2) Manifold Absolute Pressure (MAP) Sensor
(3) Evaporative Emission (EVAP) Canister Purge Solenoid Valve (4) Knock
Sensor (KS) (5) Engine Block Heater (6) Engine Coolant Temperature (ECT)
Sensor (7) Camshaft Position (CMP) Sensor (8) Generator
Good luck.
SOURCE: trying to find out where a knock sensor is located
There are 2 knock sensors on some of those, one screws into the block drain near the starter the other near the left exhaust manifold.
SOURCE: how do i change the knock sensor on 2004 gmc yukon
The person who stated they are under the intake manifold is a tool! They are located below the exhaust manifold(one on each side) and are quite simple to replace. Be sure not to overtighten them as they can become too sensitive and may cause detonation. Should be about 16 ftlbs but I would check to be sure. They run about 55 dollars each aftermarket and are about 85 from GM depending on where they are purchased from.
6,828 views
Usually answered in minutes!
×