Xantia knock sensor location ?

Mandrake · Post by **Mandrake** » 09 Apr 2006, 06:57

Hi All,

Does anyone happen to have a picture of exactly where the knock sensor is on the 2.0 litre petrol 8 valve Xantia ? The engine type is XU10 / RFX.

I have reason to believe the sensor on mine is intermitantly faulty (or the wiring to it) but without being able to identify where it is with certainty I can't check it.

Am I right in thinking that its a piezo electric transducer and that I should be able to connect an oscilloscope to it with the engine running to see if the sensor is working ?

Regards,
Simon

f00lzz · Post by **f00lzz** » 09 Apr 2006, 08:38

Sorry, don't have an answer for you....but I just noticed that it is your 'birthday' tomorrow 1year old

AndersDK · Post by **AndersDK** » 09 Apr 2006, 12:48

Knock sensor ? I believe the XU series engnes left that sensor out years ago with the BX 16V.
Never heard of it on a 2.0L 8V Xantia ?

If you're certain it is fitted on the RFX variant it will most likely be rearwards on the block - looking like an extended core plug with a wire.

Otherwise you're right on the principle and measurement setup. It works exactly like the '50/'60 style cristallic microphones & pickups. Dont even have to run the engine at idle. Tapping on the block with a steel tool will make the sensor picture itself on the Scope screen.

deian · Post by **deian** » 09 Apr 2006, 13:17

scientific but simple

Clogzz · Post by **Clogzz** » 09 Apr 2006, 14:56

f00lzz wrote:it is your 'birthday' tomorrow 1 year old

Happy birthday, Simon.

And congratulations for 899 highly technical posts.
You haven’t wasted any space, unlike me.

AndersDK wrote:Knock sensor ? ... Never heard of it on a 2.0L 8V Xantia ?

Many thanks for this valuable information, Anders.

That explains why it sounds like the knock sensor never works when using low octane fuel.

PowerLee · Post by **PowerLee** » 09 Apr 2006, 17:31

Im pretty sure the XU10J2 knock sensor is screwed into the front face of the engine block, The fact is its well hidden under other bits & pieces & a swine to get at.

AndersDK · Post by **AndersDK** » 09 Apr 2006, 17:59

So if you find that knock sensor on front of the engine block - I really made my day - right ?

PowerLee · Post by **PowerLee** » 09 Apr 2006, 19:13

Just had a look at a XU10J2 diagram for the 405, Xantia should be the same but no guarantee

The knock sensor or pinking sensor as Peugeot call it part number 5946 15

Looking from the front of the car, Its bolted on the front of the engine block towards the left hand end with a green plug connecting it to the wiring loom.

Its in line with the oil filler cap but its down the front of the lump.

I remember seeing it when I was a 405 owner & it was a right sod to get to.

Mandrake · Post by **Mandrake** » 09 Apr 2006, 20:48

There is a sensor about 2/3 of the way down the block on the front of the block, but it's on the opposite end to the oil filler cap....I'll try and take a picture of it tonight to see if anyone recognises it.

Yes the 2 litre 8 valve Xantia's have knock sensors Anders, the (later?) 16 valve ones dont.

Regards,
Simon