Testing knock sensor?


New Member
Jan 12, 2005
Well we changed the tranny in my 85 GN and ever since ive registered no knock on my scanmaster, even when i turn up the boost to about 15psi on 93 octane. Im kinda scared to get on it much right now until i know that somthing's not wrong with it. Is there a way to test it? Would it give me a code if i had messed up the wire or something going to it? Thanks for any help.
I'm not sure if it would throw a code, but to test it you'd need a DMM or scope and just tap on the block near it.
Yeah just use the handle-end of a screwdriver or something and tap near the sensor, you should get a reading.
The sensor is beneath the coil pack. To change it you have to remove the coil but you may be able to tap near it witn a screwdriver if you can squeeze in there. If you changed the tranny it might have gotten hit and was damaged. It is right near the bellhousing, so that is a possibility. Of course you could just have something banging around from the tranny swap(cooling lines, loose converter, etc..)

I would check all the bolts and lines before changing the sensor. Unless less of course you can see if its cracked or broken.

For what its worth, I fought with knock problems with only 14 lbs of boost for 6 months . I changed parts and tightened everything down I could find. All it was was crappy gas..I now run 110 octane and 24 lbs boost...no knock!

If you eleminate all other possiblities the simpliest one is probably the answer.