When I bought this truck over 4 yrs ago, the knock sensors were throwing a code. I had a previous 2001, and knew about how apparently water got in there, but never changed em out. Being as I never had cause to tear into an LS motor, I didnt know how easy it was to get the intake manifold off. So I called some shops and they said it would be a 5 hr job to pull intake, replace sensors and put it back together. They all wanted about $5-700 bucks.

Last monday and tuesday I helped Nicksilverado swap heads and cam on his 6.0, then we started pulling his 5.3, and Ben got there and jumped on the intake and had it out in no time. after I saw that I was like damn. Easy Peasy Lemon Squeezy. So this evening I decided to pull mine and look around.

Well I had it out in 30 minutes. So that leaves 4.5 hrs to clean and re-install lol. Nicks 5.3 had a huge amount of debris and leaves under the manifold, and Ben assured me mine would too since my truck was a mud truck for the first 100,000 miles. It has a pretty good amount of junk in there. I'm about to close it up for the night and start again tomorrow.

Any tips on pulling/cleaning/replacing/sealing the sensors would be welcome. Didnt really wanna pay $54 a sensor but hey.






A penny stuck in the mud

 

that is freaking nasty lol!! put a light flim of sealant around the gromet before installing that should keep any liquids out...

you really need a tbss 90mm intake and tb

 

I'd replace the sub-harness to the sensors as well as the sensors, and, as mentioned, build a "dam" of RTV around where the sensor grommets go into the valley cover. There's a TSB that outlines the RTV dam that I'm referring to, it has been covered here a few time and there are pics probably both here and in the GM general section if you search for "knock sensors"

 

def. replace the sub harness.. im 1 of those idiots that had to do the job twice... the sensors and harness have to be replaced in together if u dont want more problems later....

 

Thanks for the advice on the sub-harness. I'll do some research to save you guys some typing. If I dont find what I'm looking for, I'll come back here!

 

Definitely do the sub harness. It's about $50 if I remember right, but definitely worth it.

Make sure you torque the sensors to EXACTLY 15 ft-lbs.

This is how I applied the RTV around mine.

 

Oh yea, almost forgot about that, VERY important...if you over torque the sensors it will make them over sensitive and you'll get 7.9* of knock retard every time you tip in the go pedal.

 

Nice, thanks for the advice guys. Bout to hit er again...

 

that is nasty looking. makes me cringe to see any kind of that dirt even thought of on my setup.

 

once we take your setup 4 wheel'n we'll see how much you cringe and im not talk'n about your scooter lol