Knock sensor

[sdbartho at cca.rockwell.com]

Anyone know what voltage levels I could expect out of a knock sensor
on a GM V-6? Are we talking millivolts, microvolts, what range of 
values?

I want to build a simple knock indcator light that lets the driver
know when knock is past a reasonable level. The race PROM disables the
factory boost/timing retard vs. knock mechanism. 

The plan right now is to use a low input current op-amp fed into a
FET to drive a lamp. Am I missing something obvious? How can I 
"excite" a knock sensor? (Ball-peen hammer ain't gonna cut it) 
I was thinking along the lines of a 5 khz signal generator tied to a 
speaker, or is there a better way?

Wild guesses and speculation appreciated, too.

Dig
sdbartho at hwking.cca.rockwell.com