michaelgeorge
07-12-2007, 05:22 PM
The knock sensor is basiclly a small microphone that can pick up any sounds of detonation from the engine (pinking) due to lean mixture etc.
This clever device works constantly giving feedback to the ecu and controls timing fueling etc.
After a long period of time the knock sensor can become faulty and cause problems.
Imagine an earing aid thats low on battery life and you will be getting the idea (basiclly it can not hear so well).
Now it is very interesting that this device is so clever at picking up sounds it can tell a pinking sound from any other sound that the engine makes.
The problems start when the unit gets old because it cannot detect a pinking sound as it did when it was new and so starts picking up other sounds that the engine makes.
Now the weird bit:
The knock sensor can pick up loud exhaust noises when its (wearing out) and thinks theres a problem with the engine so being a clever little device starts to alter alll manner of things to compensate for this (ie) timing fueling etc.
(I have it on very good authority from a well known racing team that the above does happen).
If you have fitted a remus centre section onto your car and say a good rear box or duplex system and the knock sensor or sensors are old and seen better days it will without doubt be picking up noise from your exhaust system as well as the engine itself.
The answer is to fit a new knock sensor or sensors to your car.
I recently did this to my own car as it had covererd 88,000miles and still had the original sensor on it.Also the other reason is that i have a remus centre section and a magnex twin 3.5inch round tailpipe back box.
I had no management light on to say there was a problem with the car at all or the knock sensor itself was faulty.
After putting a new knock sensor on and doing a battery re-set i took the car for a spin and did the specified mileage to get the ecu to work everything out.
I can say with hand on heart that the new knock sensor has transformed the car better fuel economy faster acceleration smoother all round in all gears in fact the car felt like new to drive.
Recently i adviced someone else on this as he has an vectra MSD 2.5 GSI which have 2 knock sensors fitted which has done 75,000miles and has the original knock sensors on it.The said car has a remus centre section and a scorpion back box with twin 3.5inch tailpipes.He too had no management light or stored codes present.
I am glad to report he has found exactly the same findings as myself.
As said in previous threads the cam and crank sensors just pack up they do not start giving intermitant faults but the knock sensor can start to miss read imformation from engine sounds and surrounding areas.
My advice would be if your car has a reasonable amount of milage on it and the knock sensor or sensors have not been changed then think about it it will do no harm changing them.
VECTRA B X25XE KNOCK SENSORS
http://i243.photobucket.com/albums/ff107/michaelgeorge/23_1.jpg
PLEASE NOTE ALL VECTRAS HAVE KNOCK SENSORS BE IT ONE OR TWO.
This clever device works constantly giving feedback to the ecu and controls timing fueling etc.
After a long period of time the knock sensor can become faulty and cause problems.
Imagine an earing aid thats low on battery life and you will be getting the idea (basiclly it can not hear so well).
Now it is very interesting that this device is so clever at picking up sounds it can tell a pinking sound from any other sound that the engine makes.
The problems start when the unit gets old because it cannot detect a pinking sound as it did when it was new and so starts picking up other sounds that the engine makes.
Now the weird bit:
The knock sensor can pick up loud exhaust noises when its (wearing out) and thinks theres a problem with the engine so being a clever little device starts to alter alll manner of things to compensate for this (ie) timing fueling etc.
(I have it on very good authority from a well known racing team that the above does happen).
If you have fitted a remus centre section onto your car and say a good rear box or duplex system and the knock sensor or sensors are old and seen better days it will without doubt be picking up noise from your exhaust system as well as the engine itself.
The answer is to fit a new knock sensor or sensors to your car.
I recently did this to my own car as it had covererd 88,000miles and still had the original sensor on it.Also the other reason is that i have a remus centre section and a magnex twin 3.5inch round tailpipe back box.
I had no management light on to say there was a problem with the car at all or the knock sensor itself was faulty.
After putting a new knock sensor on and doing a battery re-set i took the car for a spin and did the specified mileage to get the ecu to work everything out.
I can say with hand on heart that the new knock sensor has transformed the car better fuel economy faster acceleration smoother all round in all gears in fact the car felt like new to drive.
Recently i adviced someone else on this as he has an vectra MSD 2.5 GSI which have 2 knock sensors fitted which has done 75,000miles and has the original knock sensors on it.The said car has a remus centre section and a scorpion back box with twin 3.5inch tailpipes.He too had no management light or stored codes present.
I am glad to report he has found exactly the same findings as myself.
As said in previous threads the cam and crank sensors just pack up they do not start giving intermitant faults but the knock sensor can start to miss read imformation from engine sounds and surrounding areas.
My advice would be if your car has a reasonable amount of milage on it and the knock sensor or sensors have not been changed then think about it it will do no harm changing them.
VECTRA B X25XE KNOCK SENSORS
http://i243.photobucket.com/albums/ff107/michaelgeorge/23_1.jpg
PLEASE NOTE ALL VECTRAS HAVE KNOCK SENSORS BE IT ONE OR TWO.