Knock Sensor 1 & 2 Mean Value

Hi All,

I recently measured my 2001 525 knock sensor 1&2 mean value (voltage) and made a trend chart. From the chart below, the knock sensor 1 variation is higher than knock 2 which remained mostly at 0.1V. I have clueless why the knock sensor 1 mean value is higher than 2. Does it normal?

P.S: Sorry for the X and Y axis description.
The correct X is Time (X 5 sec)
Y is voltage

What codes are stored?

If none, I don't think these variations mean anything. Probably just a device difference.

No error code. I feel my engine is vibrating while stop for traffic light and I check the knocking sensor mean value and sensor 1 variation is higher than sensor 2 and I am curious about this.

If one or the other sensor is bad, I would expect that you'd get the CEL. A rough idle is caused by other things, like worn-out spark plugs, intake air leak, or dirty injectors.

Is it possible the sensor works and it indicates something wrong with the engine which may be caused by other issues such as intake air leak or dirty injectors?

The Disa valve can go bad and a knock sensor will pick up on it--if that happens this can cause the engine
timing to be retarded.

What ends up with the engine timing retarded?

Power is down along with performance

Does engine timing retarded impact to knock sensor?

The engine timing will be retarded upon the knock sensor picking up what is determined to be a knock
Disa valve can go bad and the knock sensor can pick up on this and sence that there is a knock in the engine and then retard the timing--check up on the DISA valve and see if it's working correctly---you can lay your left ear on it while the enginbe is at idle and if it's clicking and making a racket in there--it's gone bad and needs to be replaced.

Originally Posted by edjack

If one or the other sensor is bad, I would expect that you'd get the CEL. A rough idle is caused by other things, like worn-out spark plugs, intake air leak, or dirty injectors.

+1. You are looking in the wrong place.

What is CEL?

Originally Posted by edjack

If one or the other sensor is bad, I would expect that you'd get the CEL. A rough idle is caused by other things, like worn-out spark plugs, intake air leak, or dirty injectors.

OK. I will check it tonight. But I remember I did this last week and did not note anything strange in DISA valve.

Originally Posted by poolman

The engine timing will be retarded upon the knock sensor picking up what is determined to be a knock
Disa valve can go bad and the knock sensor can pick up on this and sence that there is a knock in the engine and then retard the timing--check up on the DISA valve and see if it's working correctly---you can lay your left ear on it while the enginbe is at idle and if it's clicking and making a racket in there--it's gone bad and needs to be replaced.

From my feeling, I do not feel my car has rough ideal.

Originally Posted by 540 M-Sport

+1. You are looking in the wrong place.

Do you hear any strang noise from my car's DISA valve? I didn't hear.