RX300 Knock sensor errors

[Alun Jones]

I guess this has been asked may times previously.   Lexus RX300 2005 3.0V6 petrol AWD

I have errors P0325 and P0330.  sensor 1 has been intermittent for a while, now 2 causing issues.  When errors occur. the car is loosing power and transmission acting strangely so assume both sensors need replacing.

I'm struggling to find the OEM sensors on the web ( and guess genuine will carry a hefty premium ) but Autodoc are listing some Hearth+Buss, Meat&Dorta and AutLog, alternatives ranging from £30 to £60 each

Any recommendations which of these might be a good choice?  due to the manhours involved in changing,  I'm hoping to do this only once.

[Herbie]

3 hours ago, Alun Jones said:

Any recommendations which of these might be a good choice?  due to the manhours involved in changing,  I'm hoping to do this only once.

Sorry, no idea about which one to use but I've just looked at the workshop manual and yes, looks a very time-consuming job.

Given that, have you tested the sensors to make sure that they are the problem? The error codes are really only an indication of where to start looking, not an absolute guarantee that the sensors really are faulty and replacing them will cure the fault.

[PCM]

11 hours ago, Alun Jones said:

I guess this has been asked may times previously.   Lexus RX300 2005 3.0V6 petrol AWD

I have errors P0325 and P0330.  sensor 1 has been intermittent for a while, now 2 causing issues.  When errors occur. the car is loosing power and transmission acting strangely so assume both sensors need replacing.

I'm struggling to find the OEM sensors on the web ( and guess genuine will carry a hefty premium ) but Autodoc are listing some Hearth+Buss, Meat&Dorta and AutLog, alternatives ranging from £30 to £60 each

Any recommendations which of these might be a good choice?  due to the manhours involved in changing,  I'm hoping to do this only once.

Similar?

 

[steve2006]

Genuine are ridiculous at around £175.00 each ( 89615-12090.)

Amayama have them in stock for around £95.00 but by the time you have paid shipping and possible VAT you’re approaching UK prices.

The ones you are looking at do at least carry a 2 year warranty but of course this would not cover the labour costs.

Of course the Chinese make them for £25.00 for both including the wiring loom but that is risky given the work involved in replacement.

 

[PCM]

I read lots about the Chinese ones.

As you say, given the labour involved ... better to get ones you will trust.

[m4rkw]

17 hours ago, Alun Jones said:

I guess this has been asked may times previously.   Lexus RX300 2005 3.0V6 petrol AWD

I have errors P0325 and P0330.  sensor 1 has been intermittent for a while, now 2 causing issues.  When errors occur. the car is loosing power and transmission acting strangely so assume both sensors need replacing.

Never assume! Error codes are not indications of a specific fault, they are indications of an error *condition*. A quick google suggests there are at least a few possible causes, some of which are also conditions not specific faults that could likely have 100+ other possible causes - https://www.fixdapp.com/blog/p0325-code.

Take the car to someone who knows how to diagnose it, if you start throwing parts at it trying to fix an undiagnosed problem you'll run out of money before you run out of guesses.

[Alun Jones]

Just posting an update. After getting a mechanic friend to dismantle everything to get at the sensors, it was apparent that the wiring harness to both sensors was badly corroded, as well as the tag in the sensors. While I may have got away with just a harness, the amount of work to dismantle again would not have been worth the risk. Bit the bullet and bought 2 genuine knock sensors from Lexus as well as wiring harness, gaskets and a bypass hose at £560 ( plus £275 labour and new coolant at a mate rate ). Car is running really well again with no errors even after a few weeks.

Thanks to everyone for your comments.

[PCM]

Great!

My wiring harness was also VERY corroded.