Code Po332

[Andy4639]

The knock senor code P0332 keeps coming up on the scan gauge.
The truck seems to be driving just fine though.
Back when I had the truck at Hawks the passenger side O 2 senor wire was laying on the header and had melted it some. Do you think this could cause the false code? Bruce said it looked OK to him so we left it alone and tie wrapped it up off the header.
I know the knock senor and o2 senor read off each other so should I get a new one installed. I'm assuming the passenger side is bank 2 correct.

[68basket]

knock sensor problems are fairly common on these engines. they are under the intake and can take on water. Your melted o2 sensor wiring probably has nothing to do with the knock sensor codes. If it was mine i would replace the knock sensors and the wiring harness going to them, they are all available at most part stores.

[Daaaanz67]

I put a bead of silicon on The rubber plugs before pushing them down over the holes. I've heard the same thing about water issues especially if one likes to wash their engines.

[littlevictories]

just the one? might be a wiring thing. IIRC the sensors ground through the engine so gotta make sure the engine grounds are good. My ho2s's were iso-grounded through a tan wire in the harness it went to a splice pack.

You used a new harness and proper ac-delco knock sensors right? Ask me how I know do to do that, lol.

[BR3W CITY]

Andy are you sure its driving fine? Knock and misfire codes tend to prevent lockup in o/d.

I'd think the o2 would throw its own code, or run differently if the wiring were affected. O2 heater circuit will throw its own code (if heated), and you also usually get a rich or lean condition depending how it failed.

That code is bank2, so passenger side. (i think the other one is p0326 or 7) Look for shorts on the lead, the sensor to be loose or overtight etc. As always, check that you have a good part in there.

[Andy4639]

I used new senors and wiring when I installed them. I had one of the wires clips on the orignal was broken so I replaced the whole thing.I hope I don't have to take the intake all back off again. I guess I need to check the wiring and grounds.

[68c10airstream]

Hi Andy, i ran across some info about false knock sensor activity caused by motor mounts being too rigid. I believe these style of knock sensors work on the principle of when knock and noises are present the sensors create a proportional voltage on the wiring lead which is read by the pcm. This principle is called piezio electric. I have seen noisy lifters causing codes and a lazy performance from the engine (noisy lifters are not typical of ls's but i did replace one on a friends 5.3). I remember now where i read the false knock sensor activity thread, it was on a mazda miata with ls engines installed with rigid mounts. Good luck, Brian Fuller

[Andy4639]

A little update.

Now that I have the working check engine light working! I have been watching it for the P0332 code and when it does it is only when the engine is cold and I hit the gas pretty hard on take off.

Now for the past 3 days I have been checking it and when I first start the truck to go to work are to come home. The first hard take off it will set the code. Ok then I clear it right quick with the scan gauge while driving it and it want come back on. It's fifteen miles to work with several stops so I try and get it to set again but it hasn't for three days now. But every morning are afternoon with the first hard take off it does but not after that. What do you think it is sorry gas? I'm running the cheap stuff. I think I'll fill up with the mid grade and see how it does.

[littlevictories]

cold piston slap setting it off? i can buy that. maybe let it warm up before you take off and see if it'll set the code?

i know, so passe and carb-era to let a vehicle warm up before you drive it. cant believe we used to live like such heathens such a short time ago...

[Andy4639]

Originally Posted by littlevictories

cold piston slap setting it off? i can buy that. maybe let it warm up before you take off and see if it'll set the code?

i know, so passe and carb-era to let a vehicle warm up before you drive it. cant believe we used to live like such heathens such a short time ago...

That's what I'm wondering also. Yea it's kind of like dang I got to go now, right now! Ha I will try it in the morning and see what it does.

[Andy4639]

I just found this on the net also.
I know about the water but I replaced everything new when I got the motor. I guess I'm going to have to remove everything and clean the knock senors really good again.


http://www.autorepairinstructions.com/?p=224

[littlevictories]

Well, if you've got to get back in there and get at them just know you are not the only guy to do so

[Andy4639]

Originally Posted by littlevictories

Well, if you've got to get back in there and get at them just know you are not the only guy to do so

I may try some other stuff as well, like a heavier oil maybe.

[BR3W CITY]

Originally Posted by Andy4639

I may try some other stuff as well, like a heavier oil maybe.

I hope the wink makes this a joke. If your adding oil viscosity to compensate for knock, then you might as well be driving a grenade.

[Andy4639]

Originally Posted by BR3W CITY

I hope the wink makes this a joke. If your adding oil viscosity to compensate for knock, then you might as well be driving a grenade.

Well from what I have read on the net it almost as if there is nothing much you can do about it except take it a part and put new ones in it which I have already done. Some of the other forums have had people say by changing the oil they used helped.

I don't know at this point what I should really do except replace them and then I'm taking the same chance as now.
As I stated before the truck seems to be running fine and it is going into over drive by the tach. So I don't know what is causing it, it may just need some good premium gas ran through it for awhile.

[Custom 68]

Andy
I would talk to your tuner. First off to see how he tuned it. I assume you and he talked about the tune and if you wanted a more aggressive tune requiring a "better" fuel. I really don't think that is it since it only does it when cold. If it were "pinging" I think it will only get worse when the temps get hot and your truck is hot.
Secondly there are some "tricks" if you will on how to desensitize the knock sensors to compensate for the "false knocks".
I just looked back and looks like Airstream is on the same track.
I am betting on some piston slap some of the motors are notorious for that.
One last question, and I know your hearing is shot but by chance can you hear any of this knocking or is it quiet enough and short lived enough that you don't hear it at all?
The best thing would be to log it if possible to see what is going on when this happens.
Good luck
Dave

[Andy4639]

Originally Posted by Custom 68

Andy
I would talk to your tuner. First off to see how he tuned it. I assume you and he talked about the tune and if you wanted a more aggressive tune requiring a "better" fuel. I really don't think that is it since it only does it when cold. If it were "pinging" I think it will only get worse when the temps get hot and your truck is hot.
Secondly there are some "tricks" if you will on how to desensitize the knock sensors to compensate for the "false knocks".
I just looked back and looks like Airstream is on the same track.
I am betting on some piston slap some of the motors are notorious for that.
One last question, and I know your hearing is shot but by chance can you hear any of this knocking or is it quiet enough and short lived enough that you don't hear it at all?
The best thing would be to log it if possible to see what is going on when this happens.
Good luck
Dave

Thanks David and yes it has only happened once everytime I drive it and it's cold. So far after it warms up and I clear the code it's gone until the next cold start. I'm going to a car show Saturday so I will see how it does then.
No I don't hear no knocking at all are pinging! Nothing that's what has me wondering what it really is.

[BR3W CITY]

I had to go back n check, your using an 01 right?

It is definitely still a possibility, but considering your in SC, your idea of "cold" start is probably different than mine. I can start my 03/04 6L in any weather (down to about 44* is the coldest I have stuck her in) without the issue.

The fact is, GM pretty much "Waited" past this one. You can try running seafoam through the injectors, vacuum system, and a bit in the oil (right before a change) to see if it removes many carbon deposits. Thats the only "other" solution GM had for piston slapping engines.

Have you noticed any oil consumption? GM kept changing its TSB's to reflect different levels of oil use. If your not passing any oil, then it may not actually be piston slap.

Did you check exhaust gaskets near the manifold and header collector? Small exhaust leaks can get a rythmic knock until the surrounding metals and gaskets "swell" to seal it under temperature.

[Andy4639]

Originally Posted by BR3W CITY

I had to go back n check, your using an 01 right?

It is definitely still a possibility, but considering your in SC, your idea of "cold" start is probably different than mine. I can start my 03/04 6L in any weather (down to about 44* is the coldest I have stuck her in) without the issue.

The fact is, GM pretty much "Waited" past this one. You can try running seafoam through the injectors, vacuum system, and a bit in the oil (right before a change) to see if it removes many carbon deposits. Thats the only "other" solution GM had for piston slapping engines.

Have you noticed any oil consumption? GM kept changing its TSB's to reflect different levels of oil use. If your not passing any oil, then it may not actually be piston slap.

Did you check exhaust gaskets near the manifold and header collector? Small exhaust leaks can get a rythmic knock until the surrounding metals and gaskets "swell" to seal it under temperature.

I will check on these and let you know. I haven't tightened up the header bolts since they where installed, this maybe what it is. I will drive it tonight to work and in the morning after I get home I'll tighten them up good. I hope this maybe the fix.

[BR3W CITY]

I have had to tighten my header bolts on the TBSS manifolds around twice a year. My flanges were custom made and don't seat perfectly to the gaskets.

The sound often gets confused for lifter tick.

[Andy4639]

Originally Posted by BR3W CITY

I have had to tighten my header bolts on the TBSS manifolds around twice a year. My flanges were custom made and don't seat perfectly to the gaskets.

The sound often gets confused for lifter tick.

Good info on the headers.
This is my first set ever on a vehicle that I have owned so I'm learning what I need to do with them. I do think it has gotten louder inside the cab as well. Thanks.

I decided to not drive it tonight to work but I'm off tomorrow night so before I leave for the truck show I'll check them and then check them again after I drive to the show.

[Andy4639]

Checked the torque on the headers and a couple of them were loose but not bad. Drove the truck to the truck meet and sure enough it came on. I then cleared it and it never came back on until I stopped for gas and started back down the road. On the way home it came on at the first stop light sitting still. I cleared it and it never came back on. I went the long way home and had plenty of stop and go traffic but it never came back on. I didn't notice anything about how the truck was running at all.

[Andy4639]

Well now this has got me.

I just took the truck for a small ride to take some pictures of it up the street in a parking lot. It had been sitting for about 2 hrs since I drove it last. The knock senor code didn't come on either!

[Custom 68]

good deal

[Andy4639]

Originally Posted by Custom 68

good deal

I don't understand it. It's been coming on 1 time everytime I restart it. As long as it stay's running it never comes back on.