P0332 (Knock Sensors) Throwing Engine Code

[BlizzardX23]

I was throwing the P0332 while getting a tune from Justin...he told me it was the knock sensors...I replaced them...I replaced both of them...cleared the code...its been running fine...the code just came back up 2 days later....wtf???

Any help is appreciated guys!

 

[badtothe bone]

GM developed a procedure for replacing the knock sensors a while ago.

It involves replacing both knock sensors and both wiring harnesses going to the sensors.

You then build a small mountain of RVT under the intake manifold to divert the water away from the sensors wire boots, you might even need to remove the foam from the one end of the intake manifold.

You then replace both intake manifold gaskets and torque the intake manifold to INCH POUNDS and not foot pounds.

If you mark all the wiring before you remove it and put it back together in the same order as what you took it apart, you should not have any problems.

If the check engine light was not on before you started to do the power tune, then chances are, unless the ports where the knock sensors were, was full of water, and unless the terminals were corroded, the problem was not with the knock sensors to begin with - but with the person / equipment that was doing the power tune.

 

[BlizzardX23]

I drove through a lot of water 2 weeks ago...so much, that it flooded and killed my engine for a few minutes...then the check engine light came on 2 days later...then I got the tune the same day from Black Bear Performance who ran his computer on it and read the knock sensor message before he did his tune...He did his tune anyways after, I came home...removed my intake manifold, both sensor sockets were FULL of water...I dried them out, replaced both sensors, the wires were fine...I RTVd the hell out of the caps so water cant get back in them...I did all this two days ago...now the check engine light came on again and threw the knock sensor code again

 

[badtothe bone]

And now you need to take it all back apart and replace the wiring harness to both sensors.

The water did not get in there all in one day. The problem is a poor design where the water can get under the intake manifold and has no way to get out.
The top of the engine does not get hot enough to burn off the water sitting on top of the engine and the foam at the end of the intake manifold does not let the water out.

The purpose of the foam is to give the plastic intake manifold some support on that end.
They are prone to cracking, especially if tightened too tight.

I have diagnosed this problem hundreds of times and the solution is always the same.

As you have already done, take the engine all apart. Clean out all the water before removing the knock sensors. Clean everything a second time. Put anti seize on the threads of the sensor. Put RVT on the new wiring harness. Build a mountain on top of the valley cover which should divert the water away from the center of the intake manifold area where the sensors are located. Put everything back together - making sure that everything is plugged in and working.

Job takes two people about 3 to 4 hours to do and a 12 pack of beer. A roll of paper towels, a shop vac, a air compressor with ******** nozzle, a roll of masking tape, a sharpie marker, a tool to remove the fuel lines, a 10 mm socket and a inch pounds torque wrench. A long extension to get the socket on the knock sensor, a 3/8 drive wratchet and appropriate socket for the sensor - some are 15 mm some are 18mm.
A can to catch the coolant from the MAF sensor. Does this sound familiar?

 

[BlizzardX23]

tape and a sharpie?


theres no more water...I sealed the shit outta the sensor ports...I havent touched water...it has to be the harness I guess? if I replace the harness which I HIGHLY doubt is the problem (I checked it to make sure it was good)...what else could be the issue?

 

[BlizzardX23]

whats the torque rating on the knock sensors? and if I did it by hand, could that be the issue? I dont see it causing that problem =/

 

[01yukonslt]

ya i tightened mine by had as well just by how it felt didnt actually torque it and my code never came back. its possible that over time water has been getting in there and corroding your wire harness. were the sensors just wet or were they rusty as well?

 

[BlizzardX23]

so I dont have to torque them to the correct spec in order for them to work correctly though?

there were puddles of water in the sockets...both the front and back...but the wiring harness was fine from what I saw =/

 

[01yukonslt]

i mean i put mine in there pretty snug but i didnt try to break it off in the hole or leave it so it would rattle out a knock sensor just needs to be in there to detect detonation and adjust timing accordingly and as long as its in there and isnt going to move i dont see why it would throw a code unless theres some other issue were the knock sensors themselves rusted pretty badly? because mine were and i went ahead and replaced the harness on the back one the front looked pretty good so i skipped it.

 

[mikeyboy]

when my truck thro up a knock sensor code it was my coil