knock sensor

[laush]

Just wanted to inqiure about the whole knock sensor issue. I am having spark knock at 2 to 3000 rpm lugging the engine automatic 4th gear. I also have piston slap of course when the motor is cold and warm; so how is this bosch knock sensor supposed to work if the motor is producing piston slap to some degree all the time ?. I cannot understand exactly how it could determine the difference between some slap and pinging . I have used 91 octane and still get that pinging noise when the motor is lugging about town. To me a device such as this one should have never been put on this motor because it could - long term damage it; for no good reason - run lean from piston issues. Anyone agree? should I relocate mine ?

[Reveeen]

Just wanted to inqiure about the whole knock sensor issue.

 

The "issue" I have with knock sensors are they appear to age over time, requiring replacement, suggested list in Canada is over $200, and I can buy a Bosch knock sensor from Saab for $80.

 

so how is this bosch knock sensor supposed to work if the motor is producing piston slap to some degree all the time ?

 

"Official" word is, that the sound while similiar, it is at a different frequency, so it should not matter. What some folks around here have done is re-locate the knock sensor, after claiming hesitation "issues", and claim re-location fixed it.

 

I have used 91 octane and still get that pinging noise when the motor is lugging about town.

 

I use "premium" (claimed 97 octane) on a 2.2 turbo and have no noises, (piston slap, spark knock @300,000 miles).

 

To me a device such as this one should have never been put on this motor because it could - long term damage it; for no good reason - run lean from piston issues. Anyone agree?

 

The knock sensor, when "triggered" sends a signal to your engine's computer telling the computer to retard the engine timing, within set limits, until the "ping" stops. By retarding the timing your engine runs in a "rich" condition, rather than "lean", so I'm not follownig how "damage" is being done.

 

should I relocate mine ?

 

I'm not sure it will "help" you, I guess it can't hurt, if you do re-locate it make sure it is grounded (the bolt), or it will throw a code, and automatically retard your timing.

 

BTW: I am knock sensor free, not wishing to be held hostage for $200+, I gave the computer 520K of resistance to look at (so it *thinks* there is a knock sensor installed).