Engine mgmt light & stuck in 3rd!

[Madein1955]

Hi all Alphardians 🫠 engine management(2005 V6 3.0) light on once up to temperature and will not go above 3rd. I assume this is "limp mode". My garages code reader says "knock sensor" but that's all. I suspect their reader not picking up import codes. Any help or advice would be greatly appreciated. Thanks - - Paul 

[Picasso]

Does sound like knock sensor issue there is 2 knock sensors worth changing both as its a pig of a job to do need to take inlet manifold off

[Madein1955]

Thanks Lee for your quick reply. I have treated myself to an OBD reader to verify. I will log progress as things occur. Do you know what would cause these sensors to fail? N.B Always used E5 petrol.

42 minutes ago, Picasso said:

Does sound like knock sensor issue there is 2 knock sensors worth changing both as its a pig of a job to do need to take inlet manifold off

 

[Picasso]

It's not fuel related its just normal wear and tear what you need to remember some of these sensors have not been replaced before if you been closer to coventry I would have read the codes for you as I have techstream software which is the proper toyota software knock sensors read the vibrations in the engine bit of advice if you do replace these buy genuine toyota only as you will want to do this job only once don't buy cheap aftermarket ones which can be found on ebay for about £40 for 2. genuine ones about £120 each 

Edited April 19 by Picasso
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[Madein1955]

1 hour ago, Picasso said:

It's not fuel related its just normal wear and tear what you need to remember some of these sensors have not been replaced before if you been closer to coventry I would have read the codes for you as I have techstream software which is the proper toyota software knock sensors read the vibrations in the engine bit of advice if you do replace these buy genuine toyota only as you will want to do this job only once don't buy cheap aftermarket ones which can be found on ebay for about £40 for 2. genuine ones about £120 each 

Many thanks for your knowledge Lee, will keep forum updated.

[Picasso]

If you need a drawing where knock sensors are located and part no.s just pm me your reg no. 

[Madein1955]

A quick update, 

purchased a OBD reader and confirmed fault code indicating Knock Sensor issue. Going to Alphard specialist on Monday for further investigation and remedial work. I have a feeling its going to sting a bit !!!! Interesting comments about the deterioration of the wiring looms in this part of the engine bay caused by large number of heat cycles. I naively thought that my Alphie being low mileage would last forever. I will keep this conversation updated as and when. 

[Madein1955]

Morning Alphardians, just to update on progress. Knock sensors and associated wiring loom replaced. Spark plugs replaced. Timing belt and water pump replaced. Although non-interference it's coming up to 20 years old. And just for fun ATF fluid and filter changed! Alphie now drives as sweet as a nut! N.B all genuine parts used😀. Take care everybody.

[Picasso]

Glad all sorted