Knock sensor -Lexus RX330

[jdw1222]

2005 RX330 - Around 140k miles

has reduced power and is throwing code for knock sensor.

Is it likely the sensors need replacement or something else to look at? anyone done this repair before? looks like the intake comes off to access sensors

 

[Chris142]

Very uncommon for a Toyota knock sensor to fail. Ours was rodent damage. Ate the wires.

 

[GR_CoB]

Very uncommon for a Toyota knock sensor to fail. Ours was rodent damage. Ate the wires.

I had 3 Toyota/Lexus vehicles kill knock sensors before 180k miles. Also know of many 4Runner owners who deal with dead knock sensors often, in 3.4L V6. So in my experience - it is weirdly common for Toyota knock sensors to fail... If new sensor won't fix it - may be rodent damage. Also for some reason Toyota/Lexus engines only "like" OEM knock sensors. Very few people actually had luck with aftermarket ones for more than a few months.

 

[Chris142]

I had 3 Toyota/Lexus vehicles kill knock sensors before 180k miles. Also know of many 4Runner owners who deal with dead knock sensors often, in 3.4L V6. So in my experience - it is weirdly common for Toyota knock sensors to fail... If new sensor won't fix it - may be rodent damage. Also for some reason Toyota/Lexus engines only "like" OEM knock sensors. Very few people actually had luck with aftermarket ones for more than a few months.

Interesting! I have 35 years working at shops. I have never seen a bad Toyota knock sensor! I have seen rodent damaged wires often.

 

[The Critic]

https://www.bobistheoilguy.com/foru...alley-plate-coolant-leak.294801/#post-4845049

Knock sensors are in the valley. Possible that the harness is the issue, but I would remove the lower intake and replace both sensors, the sub-harness and reseal the valley plate.

 

[CharBaby]

Had to replace the knock sensors on our RX300 at 130K. Had nothing but sensor problems with that SUV since yr 2.
One of the less reliable vehicles I've ever owned. Not the product of quality that I was expecting for $40K back in '01

 

[Oro_O]

Interesting! I have 35 years working at shops. I have never seen a bad Toyota knock sensor! I have seen rodent damaged wires often.

I have owned a lot of Toytotas, worked on many more, and also own this particular vehicle now with 320k on it. Never seen it happen. Was also a mod at the TN forum for a while for this series of cars (camry/avalon, etc.) - and it was not common.

Thus, my "index of suspision" with this is high, just like Chris142. If repalcing the sensor fixes it, I would still look around for something that killed the sensor. Sure, once in a while a bad one, but this is uncommon.

 

[clinebarger]

I've seen bad sensors on 1MZ-FE & 3MZ-FE engines.....It happens. But rodent damage to the Jumper Harness is far more likely.

 

[jdw1222]

Ok thanks for the suggestions. Will look into harness also

how involved is this particular engine to remove intake to gain access? Anything special needed?

 

[joegreen]

I had bad knock sensors on my 1mzfe es300. Please go with oem Toyota knock sensors from a dealer. There are many Knockoff sensors online that state they are oem. They even copy the oem Toyota packaging the sensors come in so they look legit but aren't.

 

[jdw1222]

it looks like the OEM sensors are around $175-200 each!!

See some "densos" on amazon advertised for much less. Assuming these are counterfeit sensors. Ran into that issues with Denso Spark Plugs

 

[slacktide_bitog]

If you need them, get Beck/Arnley from Rock Auto

 

[The Critic]

Ok thanks for the suggestions. Will look into harness also

how involved is this particular engine to remove intake to gain access? Anything special needed?

I posted a thread with some instructions. Look a few posts up.

 

[jdw1222]

I posted a thread with some instructions. Look a few posts up.

Thanks!

Somehow I missed your link the first time. It looks like you recommend the thermostat and bypass hose while doing the knock sensors?

 

[The Critic]

Thanks!

Somehow I missed your link the first time. It looks like you recommend the thermostat and bypass hose while doing the knock sensors?

Bypass hose, thermostat and water inlet plate, definitely.

If you feel Adventurous, do the valve covers as well, but there is extra labor involved. You’ll have to move the harness a bit and possibly one of the Upper intake manifold hangers.