Knock sensor

[sams86gn]

This will probably be a stupid question to most, but I read in a thread once that the factory knock sensor is located on the rear of the block. Well I don't see anything and don't remember seeing anything when my motor was out that looked like it would be a knock sensor. Does anyone have any pics of what it looks like? If mine is not there would my motor still run fine or would the computer not let it run? My car seems to run fine and my transmission will be back in it this weekend but I want to make sure I have everything in order before a few test drives.

 

[oldsracer]

http://www.casperselectronics.com/store2/product_info.php?products_id=939

 

[sams86gn]

Ok so it's located under the coil. to answer my next question, would my car be running without this piece?

 

[oldsracer]

I dont see why it wouldnt run but for obvious reasons I dont suggest doing it

 

[fastblackracing]

Yes it will run ok without it, BUT--- you will lose the spark retard feature that it provides and will most likely end up blowing your head gaskets. It is there to safegaurd the engine from detonation which will happen at some point.

 

[sams86gn]

Yea I get that part I just wanted to make sure before I go out in the cold looking for something thats got to be there for it to run. I will do a little investigating tomorrow and make sure it is in place

 

[sams86gn]

Just checked and it is there and plugged in. Feel alot better knowing for sure its in place.

 

[fastblackracing]

sam do you have a good understanding how the knock sensor works?

 

[highboostgn]

make sure you torque it just right or it wont work correctly

 

[sams86gn]

sam do you have a good understanding how the knock sensor works?

Not exactly. I know it senses knock and let's the computer know so it can retard timing and basically that's all I know about it. I don't remember putting it on my crate motor, would this have already been installed? Maybe I did put it on and don't remember because I have had it for over a year

 

[fastblackracing]

The knock sensor that screws into the block is wired to the ESC module, and the ESC module is wired into The ecm[the computer in the kick panel that holds your chip]. When the knock sensor picks up a vibration or knock signal it causes the ESC module to change its signal going into the ecm which then adjusts the spark timing to a reduced value based on the chip program and severity of the knock. It does not know exactly how much to retard the timing but it guesses and then re-evaluates and will either give the timing back or continue to retard it. The chip programmer determines how much he wants the timing to retard for a given knock signal and how fast to give the timing back. There can be false knock that retards the timing also and if enough timing is pulled from the system the car will basically quit pulling and fall on its face. The tightness of the knock sensor can influence how it works because it picks up the vibration in block that detonation causes, similar to hitting the block with a hammer. HTH

 

[sams86gn]

Thank you for taking the time to explain it. Now I just need to make sure it is working. As soon as I get the trans back in I will try the tapping test and make sure it is working.

 

[sams86gn]

Just wanted to give an update, the audible knock sensor is in and working. Hopefully it will help me keep everything together!