Jump to content

Knock Sensors

Michael31
 Share

Recommended Posts

Michael31 Enthusiast

Michael31

Posted
Posted

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 Senior Enthusiast

txab

Posted
Posted

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?

  • Like 1
It's Tim Senior Enthusiast

It's Tim

Posted
Posted
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 Enthusiast

Michael31

Posted
  • Author
Posted

Newdude,

 

Harness, sensors, and manifold gasket each time.

Michael31 Enthusiast

Michael31

Posted
  • Author
Posted

Txab,

 

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

BlancoSilverado Enthusiast

BlancoSilverado

Posted
Posted
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

davester Senior Enthusiast

davester

Posted
Posted (edited)

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 by davester
Michael31 Enthusiast

Michael31

Posted
  • Author
Posted

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 Senior Enthusiast

riverbanks

Posted
Posted

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 Enthusiast

Michael31

Posted
  • Author
Posted

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?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Chuck FB
      Tire psi

      By Chuck FB · Posted

      I just can't think of the exact term GM uses for that higher gvw package without looking at the website but basically sort of a trailering package and I imagine it may also have been created to skirt around the licensing fee differences between a3/4 and 1 ton that apply in some states although ironically I believe in some states its the reverse that a 1 ton is the cheaper truck to license over a 3/4 ton. It makes no difference here in Alberta but oddly enough a 1 ton through my insurance company is a bit cheaper to insure over a 3/4 ton as its based on the insurance statistics they generate.    For sure when ever you do have the chance to weigh your truck and to be fair, try to have the fuel tank full or nearly so rather than give yourself a false sense of the truck being lighter by having an almost empty tank.    In my other comment I was mentioning stock sized tires and partly in case someone was reading this and thinking they could lower their pressure down to what your aftermarket tires are able to do with your empty truck as that is a vastly different picture in the leeway you have to play with for running minimum pressures while remaining safe. I will say also that its easy to see from reactions of truck owners that may have been more used to owning a half ton in the past or a car and be it on a forum like this or in person etc that they get so wrapped up in that placard pressure sticker that they can't get their head wrapped around the fact that an HD truck due to how much it can carry can also vary the tire pressures drastically lower than those pressures ( typically more so for the rear axle on stock sized tires ) when empty vs some car that isn't made to carry much so the tire pressures can't be lowered since it needs almost that much pressure just to carry the empty car.    If I ever do find myself in the states with this truck, I will only be too happy to switch it over to the US measuring system as then I will understand all the dash readings. The only thing that is off for me slightly with US measurements is US miles per gallon as I grew up with the Imperial gallon and to this day up here anyway speak in Imperial miles per gallon ( I don't do that on this forum though as that would confuse everyone for no good reason ). 
    • jgaudet99
      Tire psi

      By jgaudet99 · Posted

      Yes that's right, it's the upgrade that includes the overload spring and all that stuff.   Someday when I'm empty and going by a scale I'm going to stop in and get some weight readings.   Exactly  you should have the ability to change individual settings, in in Canada so I'm driving with kph but then I'm stuck with kpa when I want psi lol    
    • Chuck FB
      Tire psi

      By Chuck FB · Posted

      You must have that upgraded gvw package which is only available or at least was in 2025 with the diesel engine for the 3/4 ton and that gave the truck physically the larger 12.0 ring gear rear diff and the 3500 rear spring pack. There is a difference in what the diff housing looks like externally as one tell tale and also your truck should have the upper overload spring pack and the frame pads that the pack goes up against.    The pressure the tpms system kicks the alarm in on a stock setting truck, that is a good question and was just from what I recall but I doubt I made any notes on it as I knew for the rear that it was not at all what I was after regardless either. Being that you have a diesel and if running on stock tires the minimum pressure on an empty truck seems to be around 50 psi from hearing of those that have weighted the front axle but the rear axle is very similar in weight to a gas truck and again a near empty truck on the rear could go down to 35 pounds at minimum. However the weigh scale is the proper way to know for sure as a guide.    As to changing the readings on the dash from metric to the US measuring system, oh yes that is done easily but what I was attempting to explain was that I can't pick and choose items I want to have in US and those I still want in the metric system at the same time as its either all or none. For example lets say you drove into Canada and switched your dash over to metric so your speedometer read in km an hour, well then your reading kilopascals on your tpms readout and your wife looks over and says what the hell is that saying in the tpms screen and you say "darned if I know, I think its Chinese" !
    • Chuck FB
      Some Assembly is Required

      By Chuck FB · Posted

      This is partly why I decided to have switched over to Amsoil SS as a way of hopefully preventing the buildup of the sludge/carbon on the pistons and clogging of the oil control rings and the carbon that would cause the compression rings to stick in their grooves as well as stay cleaner up top of the heads in the valve train in the first place, an oil that has tested better by third party testing over typical shelf oil and also doing my best to run relatively short OCI. However in saying that I don't think there is any way to easily prove the oil I was using prior allowed for a buildup at the OCI I was doing, nor in the other direction to make claims the Amsoil is keeping everything clean either. There really isn't a window into the engine is there to know anything for certain even if oil samples were taken for example that showed still healthy oil being dropped out of the oil pan other than engine tear downs that extensive and expensive testing of oils does to actually visually see what is really going on inside the engine. I wish there was some easy method of seeing what is going on but I don't happen to be aware of that if there is.  
    • jgaudet99
      Tire psi

      By jgaudet99 · Posted

      My truck is a ¾ ton but my placard also says 80 for the rear tires, I think I might have the upgraded suspension to the 3500 series maybe.   I put my air down to 60 and the light was still on, and there was no way I was putting over 60 psi in the rear empty and not towing because I knew the actual number Toyo gave me and I didn't wanna ruin the center of my tires!   And you actually can change it in the settings from metric or is and it will show kph or mph then when you go into your tire settings it will be either psi or kpa, but it would be nice to just change it directly on the tire psi page 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...