Knock Sensors

[Michael31]

I'm having chronic troubles with knock sensors on my 2001 GMC 2500HD 6.0L. 

I've replaced them 3 times in about as many months. The first ones were "Lifetime warranty" But they failed twice. I replace both sensors the wiring harness and manifold gasket each time.

The last set was AC Delco and now I'm having to replace them again after getting the knock sensor codes. Any insight to this hit and miss problem? 

I replace them and drive 10-14 miles and the codes are back! 

One final question? Can I reuse the intake manifold seal if it been installed for a month or less? This goes against my better judgement! But I spending a small fortune on manifold gaskets. 

I'm getting efficient at completing this work! But I don't want to be!!! Any help appreciated.

[txab]

Did you replace the wiring harness as suggested to you in your other thread on this issue? Did you torque the sensors to the correct value?

[newdude]

X2 on the harness.  Has that been replaced?  

[It's Tim]

1 hour ago, Michael31 said:

I replace them and drive 10-14 miles and the codes are back! 

A code indicates an issue with the circuit not necessarily a component as you have discovered.

[Michael31]

Newdude,

 

Harness, sensors, and manifold gasket each time.

[Michael31]

Txab,

 

Torqued to 10 ft lbs. I don't have a inch torque wrench. 

[BlancoSilverado]

18 minutes ago, Michael31 said:

Txab,

 

Torqued to 10 ft lbs. I don't have a inch torque wrench. 

oriellys, autozone you can rent one for free. 

 

harbor fright, you can buy one for less then $30

[Michael31]

Tim,

Any suggestions on what to look into.

[davester]

Maybe post what codes are being generated.

 

Just replacing the short harness from the knock sensors to the rear of the engine isn't enough.  Depending on what code is being generated, there could still be a wiring harness problem past where the stub harness connects (between it and the ecm).

 

As well, knock sensors are sensitive to being damaged by say, being dropped (even in their packaging, even more before you ever saw the part).

Edited March 10, 2020 by davester

[riverbanks]

In the other thread you had 02 codes,all gone?

[CamGTP]

I thought the torque spec was 15 ft lbs, been a few year though.

[txab]

^^ Correct

[Michael31]

Riverbanks,

I had only the P0327 and P0332 codes last time I had the check engine light come on.

 

I think your right 15 lbs? I was thinking the manifold torques.

[riverbanks]

So you started off with,332,327,171,172,174,175,507 and 101,you cleaned the MAF,many have now disappeared,you didn't say who's MAF it was,might better get a Delphi MAF,or change the knock sensors a few more times

[Michael31]

Yes, All the codes are correct.

 

I've been able to erase and the codes with up grades and searching for leaks.

 

As of now I only have the 2 knock sensor codes.

 

The prior knock sensors were "lifetime Warranty" but low quality, swapped them for ACDelco sensors now. 

 

I've checked out the harnesses and sensors before installing them. Used a vise to hold the sensor and tap on the vise and check the reading with a multi-meter. I also checked the sensors after removal and they were faulty.

 

Am I looking in the wrong area for a fix?