Just found out from autozone that my Lexus ES 300 1994 has knock sensors that need to be replaced but don’t know where they are and if it’s worth fixing?
If your car runs good then they're worth replacing.
They're under the intake manifold.
There are two knock sensors.
Also a short wire harness to connect them.
Also a coolant bypass hose.
While you have the manifold off replace all of them.
(knock sensors part number 89615)
I am about to buy a 2003 Lexus RX300 for my daughter. It has the check engine light on for the knock sensors, but no emissions inspection is required where she lives. The vehicle runs perfectly fine and I am not replacing the sensors.
For some reason autozone said my knock sensors where the cause for my coolant to overflow out the tank and boil up
I would love to hear their explanation of that. I have read that bad knock sensors can prevent a transmission from shifting into overdrive, which would cause the engine to rev higher and be less fuel efficient. Even then I don't think running at 3 to 4000 rpm would cause overheating. That said, I would replace them if your car is not shifting correctly.
The shifting is perfect and smooth I just have the problem with the coolant coming out it’s tank I just was told that my check engine was from those sensors
I would look for the common causes of overheating like bad thermostat or radiator fan. Really doubt the knock sensors are involved. If you have to pass emissions, you will have to replace them.