Knock Sensor Replacement

[00silver]

I have some spark knock at lower rpms both with high and normal octane fuel. I've read about the spark knock sensors getting moist and then requiring replacement. Since I DO clean under the hood, it seems possible I have one bad.

If I remove the intake (to gain access) on my 5.3L '00 Silverado can I reuse the head gasket? I know I need to replace the intake gaskets...about 25-$30, but the head gasket is listed at over $200

[chuck16]

When it comes to water and Oil I would imagine getting a new Gasket is a pretty Safe bet! God Damn GM putting the sensors in there....

[BlenderWizard]

Originally Posted by chuck16

When it comes to water and Oil I would imagine getting a new Gasket is a pretty Safe bet! God Damn GM putting the sensors in there....

I do not understand why you need a new head gasket if you are just pulling the intake manifold

[chuck16]

Originally Posted by BlenderWizard

I do not understand why you need a new head gasket if you are just pulling the intake manifold

Sorry I was just answering his question about re-using the gasket. So, yeah if you pull the intake off I guess there isn't any water connections there is there? I'm honestly not sure haven't taken a real close look... I'd have to look in my Haynes manual to be a 100% sure on this procedure...

[maxwedge]

Before doing this, scan the engine and look for percentage of timing retard as a result of the knock sensor activity, also remember a poorly operating egr system can cause engine knock also, you are getting way ahead of yourself pulling this apart. There may even be some pcm reprogramming issues or tsb's relative to this condition, look at alldata.com for the basic tsb titles.

[00silver]

AllData is where I got the original info. about the gaskets. They state to separate the intake gasket from the head gasket. I didn't understand that either, unless the intake comes in thru the side of the head....

[BlenderWizard]

might try here: http://www.automotiveforums.com/vbul...d.php?t=338757

[HanibalTheCannibal]

I have same knock issues. GM told me I had latest calibrations (yeah right). Allen (Nelson Performance) told me his tunes would clear it up. It seems these need a tick more advance timing curve.

[LongIslander26]

Originally Posted by 00silver

I have some spark knock at lower rpms both with high and normal octane fuel. I've read about the spark knock sensors getting moist and then requiring replacement. Since I DO clean under the hood, it seems possible I have one bad.

If I remove the intake (to gain access) on my 5.3L '00 Silverado can I reuse the head gasket? I know I need to replace the intake gaskets...about 25-$30, but the head gasket is listed at over $200

The knock sensors are usually located UNDER the intake manifold in the lifter valley, so that's why you need to remove the intake. (Assuming you decide to replace the sensor) You'll see a wire coming out of the lifter valley pan when you get the intake off. I imagine you meant "Intake gasket" and not "Head gasket". GM has had alot of problems with these gaskets leaking.(There is a TSB concerniong this problem) If you get the intake off, and the gaskets are an orange color, I would replace them. GM has come out with a redesigned gasket that is a lime green color. Seeing as how you're going to have the intake off anyway (Maybe), you may as well replace the gaskets with the updated ones to save yourself having to do the job again later down the road. Just remember to wire brush the intake bolts, and use some red loc-tite on them, as GM only calls for 11 ft/lbs of torque to tighten them with, which makes them prone to loosening up over time.

(p.s., I may have the colors backwards, you may want to give your local Chevy dealer a call to get the correct info)

[BlenderWizard]

Originally Posted by HanibalTheCannibal

I have same knock issues. GM told me I had latest calibrations (yeah right). Allen (Nelson Performance) told me his tunes would clear it up. It seems these need a tick more advance timing curve.

Absolutely, Allen will. I got my truck, used, back in March, with 25,600 miles on it. It had a pretty bad pinging to it when using 87 octane (which it specifies in the owner's manual). Later (June 1), I got a Nelson Tune. This cleared up a lot of my pinging. I explained to Allen that the truck had been pinging before the tune, and it was better after the install, but it was still present. He retuned it with a little less timing. Pinging cleared up. Pinging came back a couple months later and was only VERY slight, but ever present. Called Allen again, told him the situation. He did me up another tune and pulled a little more timing. I installed this one last week, and have put 600+ miles on the truck (got it to or past 100 a couple times) and no pinging. Allen is very, very good about working with you to correct things that he, in no way, had anything to do with.

[jeverett]

Hmm...maybe I need to pull some timing from mine? It has beenpinging for like 2 years. Maybe after my 02 pcm..if i can find another one ^@&#$#