Good afternoon. My name is Van. I'm new here, so any help or advice getting around on this website would be appreciated. That said, I would like to present my dilemma for consideration. I have a recently acquired 2005 Silverado 4.8 v8. It started giving me a P0332 after about a month. My reference tells me that is knock sensor 2 circuit low input(bank 2). After some more reading, I'm hearing the rear knock sensor is prone to collecting moisture and causing corrosion of the knock sensor, especially if engine has been washed. I vacuumed the debris at the runners and pulled the intake. I was carful to keep debris out of heads. I blocked off the heads and cleaned the surfaces carefully. I bought two new knock sensors and a new harness, and an intake gasket set. The rear knock sensor was rusted up pretty bad. I cleaned out the cavity and installed the new sensors and torqued them at 15 lb/in. I installed the new harness, and per the GM bulletin I ran a bead of rtv around the outside edge of the rubber plugs that are attached to the new harness after I had pushed them into the cavities. I installed intake with the correct torque and sequence. Road test and no problems. Then a few days later I get P0327. I clear it with my scanner. No more problems driving around town. Today I get up on the freeway at 60mph and I get P0327 again which is the front knock sensor. I am using an actron obd II pocketscan code reader. So, I am scratching my head and realizing it's time to get in here and try to get some help before I go any further. Thanks. Van
vanbmarshall
It's possible the knock sensor you installed is bad or it just has a loose connection. If nothing else this will give your post a bump so it gets put back at the top and get some more suggestions.
Did you install AC Delco knock sensors? I did a tune up last year on my 2003 at 100k; I now have 125k on the clock and for the past week I too have been getting a P0327 code when I throttle the truck up an hwy entrance ramp. I've heard that aftermarket knock sensors aren't the best, (stupid me installed Wells sensors.) So, this weekend I get to tear the intake off again and replace the knock sensors with new Delcos. I wasn't getting any codes with the originals and the only reason I pulled 'em out is because they had 100k on them, probably should have left them in! :x
Thanks folks. I didn't install ac delco knock sensors. Maybe I should have. Everything came from Oreilly. The price is staggering for the ac delco as you may know. Before I go any further, I'm dropping it off to a diagnostics specialist I know. I'll post what he comes up with. I'm wanting to sell this one(the Chevy) asap, and I don't want there to be lights coming on after somebody else gets it. I recently picked up a 2005 GMC Sierra, 5.3, with 34000 miles on it, so I want it to be my keeper. This will be good experience because very similar except Chevy is 4.8 and GMC is 5.3. Van
To update on the 2005 Chevy knock sensor issue, the diagnostic tech couldn't find anything wrong with the knock sensors or ECM. I took it for a drive and got the P0327 again after getting it up to 65mph. He agrees with what I've been told here. He said he uses only GM knock sensors. He also said to replace both knock sensors when I take the intake off again, not just the one throwing the code. So, tomorrow I'm going to take intake off again and go to Chevrolet dealership and get 2 GM knock sensors AND the GM harness, even though I just put a new after market harness on with aftermarket knock sensors. What is the rule on reusing the felpro gasket set, that I put on when I did the job the first time? Thanks. van
Well you might could get away with reusing them but I make it a rule to always replace gaskets and seals. Nothing sucks worse then to do all that work and have to tear it all down again to replace the gaskets.
I just changed both sensors last weekend. Installed 2 new AC Delco sensors and a new Victor Reinz intake gasket set. The old intake gasket was only a year and few months old and had 22k on it but I didn't want to do this job a 3rd timeso I replaced it!!! So far no lights and engine runs smooth. I also cleaned the intake ports on the heads with SeaFoam while i was in there. I think that helped a bunch too. Hope you have success as well!
Im sorry you got bit by the aftermarket bullet. I had read online about DO NOT USE AFTERMARKET on this repair. So i bit the other bullet (the silver/gold one) and paid $175 for OEM knock sensor, ac delco intake gasket and a doorman knock harness (didnt have ac delco in stock)
I'm glad i did, codes went away immediatley and stayed away.
That being said, im glad you got it sorted out.
Let me ask you a question though, in the 3500-4000+ RPM Range, does your engine still ping? Reason I ask is because mine did this before and during the time when the knock sensor went bad, and now that i've replaced it, it still does it, it just doesnt throw a code (i guess that means the computers working) it used to throw a code every time it pinged, now it does not, but it still pings in the upper range.
I'm glad i did, codes went away immediatley and stayed away.
That being said, im glad you got it sorted out.
Let me ask you a question though, in the 3500-4000+ RPM Range, does your engine still ping? Reason I ask is because mine did this before and during the time when the knock sensor went bad, and now that i've replaced it, it still does it, it just doesnt throw a code (i guess that means the computers working) it used to throw a code every time it pinged, now it does not, but it still pings in the upper range.
No my engine is smooth and quiet thruout the entire RPM range. I use mostly Conoco Mid grade Plus year round, and sometimes I run Ethanol free gas. Maybe you need to up the octane your using.
Also on a side note, I found AC Delco knock sensors on Amazon from a company going out of business. I got 2 of them for about 60 bucks!
Hope your fix continues to work. I think you will be ok with the Dorman harness. You may want to check the condition of your spark plugs too if the have a bunch of mileage on them.
Also on a side note, I found AC Delco knock sensors on Amazon from a company going out of business. I got 2 of them for about 60 bucks!
Hope your fix continues to work. I think you will be ok with the Dorman harness. You may want to check the condition of your spark plugs too if the have a bunch of mileage on them.
Apparently my knock sensor problem is resolved. I did as suggested here. I pulled the intake off again, replaced the knock sensors and harness with parts from the local Chevrolet dealer. I sealed around the rubber plugs with rtv as suggested by the GM service bulletin. After taking several extensive "test trips", I can say the problem is resolved and I was able to sell the truck, as I had two. O'reilly auto parts credited back the parts I bought from them, but left me hanging on the labor Btw, that was $257.00 for the knock sensors and harness from the Chevrolet dealer. It sound high, but when you have to go through all of the crap I did, it's not so bad. I appreciate the comments left on this matter. Now it's on to doing the transmission service on my 2005 GMC Sierra. 35,000 miles. I went to the dealer and bought the gasket filter kit and fluid. Right at $100. Fine with me if I don't have to do it twice. I have done this service before, but any comments will be appreciated. Thanks. Van
Btw, that was $257.00 for the knock sensors and harness from the Chevrolet dealer. It sound high, but when you have to go through all of the crap I did, it's not so bad. I appreciate the comments left on this matter. Now it's on to doing the transmission service on my 2005 GMC Sierra. 35,000 miles. I went to the dealer and bought the gasket filter kit and fluid. Right at $100. Fine with me if I don't have to do it twice. I have done this service before, but any comments will be appreciated. Thanks. Van-
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