testing the knock sensor???

[Syclone#2960]

What is the best way to to test the knock sensor?

I tried tapping the the intake bolt close to the sensor with the ign key on (truck not running).

The scan tool is not showing knock counts.

Does the truck have to be running to check for the knock counts?

I replaced the memcal and still not picking up knock.

 

[midnightbluS10]

Re: testing the knock sensor???

I tested a knock sensor at school with DVOM. When I tapped near the sensor, it registered as voltage on the meter.

 

[SY-1193]

Re: testing the knock sensor???

It could depend on what chip you are running. Some of Kenne Bell 's Chips you will get nothing. Some chips do not look at knock until a certain RPM. What chip are you running? The knock sensor is a microphone you could hook it up to a 1/8" jack and plug it into a tape recorder and play back what it hears. I would replace it if I suspected it was bad - (if your chip uses it to retard timing, hopefully it does).

 

[Syclone#2960]

Re: testing the knock sensor???

It could depend on what chip you are running. Some of Kenne Bell 's Chips you will get nothing. Some chips do not look at knock until a certain RPM. What chip are you running? The knock sensor is a microphone you could hook it up to a 1/8" jack and plug it into a tape recorder and play back what it hears. I would replace it if I suspected it was bad - (if your chip uses it to retard timing, hopefully it does).

I'm running an ultimate chip for vortecs, 412, 50lbs. injectors.
I spoke with Nick who is also running the same chip. He tested his with the truck off & picked up knock counts while tapping.

 

[SY-1193]

Re: testing the knock sensor???

GM Part #10456549
Approx. Cost $36.70 - source: GMPartsDirect.com

Torque it when installing it to 14 ft/lbs. (important to torque it - too loose = less sensitive; too tight = more sensitive).

 

[Syclone#2960]

Re: testing the knock sensor???

Well I tried 4 other used knock sensors torqued to 14ft/lbs.. Then I removed the Ultimate chip & plugged in the stock memcal only...still nothing.

I'm getting 4.95 volts with the volt meter plugged in between the knock sensor installed & the knock sensor plug.

 

[midnightbluS10]

Re: testing the knock sensor???

We tested one that was completely unplugged. Every time we banged on the engine, it registered on the meter. You can also check for continuity in the sensor.

 

[Syclone#2960]

Re: testing the knock sensor???

I'm getting a reading of 3.986 on the OHM settings for all four sensors.

I think I'm going to tap around the sensor while the engine is running tomorrow.

I'm so sick of these trucks!

 

[i8av8]

Re: testing the knock sensor???

I'm running an ultimate chip for vortecs, 412, 50lbs. injectors.
I spoke with Nick who is also running the same chip. He tested his with the truck off & picked up knock counts while tapping.

yeah, i'm running the same set up and came to the conclusion that my knock sensor was bad when i would have key forward and jiggle my keys (while in ignition) and it would pick up knock like crazy.


"I'm so sick of these trucks!" no no, don't say that! the truck will here you and make things worse. we are their prisoners! when they act up it's like them saying fix me, d@mit!, and we do.

 

[nello]

Re: testing the knock sensor???

I was a bit concerned if my knock sensor was functional too.

I tested mine with the truck running, and banging on the rear of the block with a wrench. DM started recording counts instantly. Also, when starting or turning the engine off, my knock sensor registers between 3-5 quick counts for a quick second.

So far zero knock detected during boost :turbo: Though I'm sure running 100octane has a lot to do with it too.

 

[Syclone#2960]

Re: testing the knock sensor???

Well I put the rocker arms back in & started the ty and the knock sensor is picking up knock while tapping the block. Wierd.

 

[Big Mike]

Re: testing the knock sensor???

You know you should not reuse a knock sensor, I was told this by a GM service person, they can get distorted and give you false readings.

 

[Syclone#2960]

Re: testing the knock sensor???

You know you should not reuse a knock sensor, I was told this by a GM service person, they can get distorted and give you false readings.

I can see how that would make sense...some of them are stripping at the faceplate from trying to torque them down. I think I'm going to open one up to see whats inside.