Knock Sensor Question

[RonnieH]

I am getting ready to flush the cooling system on my '89 before putting it away for the winter. Regarding flushing, I have seen in related posts comments about removing the knock sensor(s) to drain the block. What is the knock sensor and where is/are it/they located? Some vehicles still have petcocks below the heads for draining the block, and they are what I have usually opened to drain the block and ensure a good cleaning of the cooling system. Previously, I have had the dealer clean the Vette cooling system every couple of years, but I am convinced I can do at least as well and probably better w/o all the expense. Plus, since it is not driven in the winter, gives me an excuse to at least get out in the garage and tinker with it and start it up from time to time. Thanks for any help you guys can provide.

 

[vetteboy86]

The knock sensor actually detects spark knock. It then sends a signal to the ECM saying that there is spark knock present. The ECM in turn retards the timing to prevent any serious damage. I know my bro just had to replace his, kind of a preventative thing.


Craig

 

[Vettefan87]

My 1987 Service Manual says to. Open radiator drain valve and block drain plugs to drain coolant. It does not show a picture of either....:ugh Someone will know where it is though.

 

[I_R_DA_ONE]

Ronnie
the knock sensor is located just below and in between the #6 and #8 spark plug...
You will need a deep socket to remove this sensor...

Mike

 

[RonJ]

I believe the knock sensor is the block drain "plug" on your car.

Ron ...

 

[Nitronick]

Ronnie
the knock sensor is located just below and in between the #6 and #8 spark plug...
You will need a deep socket to remove this sensor...

Mike

That would be your temperature sensor.
The knock sensor is located right above the oilpan rail, center of the block on the passenger side. This would also be the block drain point, and there is a plug on the driver side as well. Center of the block just above the pan rail.

Merry Christmas,

Mitch