Engine Knock started 282,375 miles

[white1]

im curious as to how he said the sensors are bad?

Me??

He has 28x,xxx miles, Ive seen them develop some corosion. I agree with you that the thing is just worn out. I was just thinking that with good knock sensors, it should retard the timing to keep any detonation out. If its rod bearings it wouldnt matter. Guess I was just throwing ideas out.

[mnc2fan]

This has not been a problem before. Last weekend I pressure washed the engine and of course getting water under the intake. Putting water under the seals messing up the sensors.. at least I agree that could be an issue.

I'm going to run it for a while without doing anything, see if my gas millage suffers. That what I was told would happen if they are bad, don't see how that would do that anyhow.

How would I know if its not the sensors? Like I said I don't hear the knock now, and the shop didn't hear it, and I let two other people listen and didn't hear the knock.

Any other ideas as to why the code p0327 is thrown pointing to the knock sensors? Would be appreciated

[GasGuzzler]

It's easy to diagnose. There's only one wire to each sensor. All you have to do is unplug the harness at the back of the engine and measure the resistance to ground on both wires. If it's out of spec (but not open), the sensors are most likely corroded. If one shows open, it's likely the wiring is open (most likely rodent damage here).

The spec is 93-107K Ohms.

There's no way in hell I'd ever reuse the gaskets or harness on a 9 year old LS with almost 300K miles. Those are two of the most failure prone parts on the truck LS engines. I'm surprised he hasn't had to replace the intake gaskets already...at least once. The harness will break apart when removed. It will also have corrosion in the terminals at the sensor end.

Magazines say the 305-350 Vortec gaskets are reusable too....

I was somewhat surprised about the prices so I looked them up. GM list is $66.84 for the sensors each, $106.19 for the gaskets (OUCH), and $41.92 for the harness.....that's where you're getting screwed a little.

Make sure they remove the foam end seals under the intake and dam up the front side of both sensor seals with sealer.

I looked up the labor and it's pretty cheap. Here it would be $280.

[GasGuzzler]

Oh yeah....ask for the parts back too....you'll see how freakin' rusty they are.

You might consider doing the repair yourself.

[mnc2fan]

Yeah I just spent about 128 on parts to get the sensors and gasket. 43.49 per sensor, and 37.99 for gaskets.

I just can't find the wire harness for it.. adavnce didn't have it. And googled a few places, no results.

So I'm looking at about 150 maybe less to fix it myself! almost quarter of the work to be done there! Glad I'm doing it.

Oh and the labor yeah that isn't really bad. Most places I know charge 65 an hour

[GasGuzzler]

We're $78.50 in the country.....in Dallas it's a lot more....$85-150 at the dealer.

Don't get the harness for now unless it's a real DD. Try and see if you can get it apart without it breaking...

[mnc2fan]

Ouch on those labor prices.. but again that is the city. I did get the harness for it. See if I can get them off without them breaking, but probably just use what I bought.

I appreciate all the opinions, help, and advice. Its really given the will to fix this myself.

Make sure they remove the foam end seals under the intake and dam up the front side of both sensor seals with sealer.

I was thinking about using silicone would that be good to use?

[RedHeartbeat]

Absolutely, be sure its a silicone adhesive.

[mnc2fan]

Awesome, just found a use for the silicone used on my lights. Been wondering what to do with it.

I'll get some pic of 300k mile sensors and wire posted. Should be interesting.

[RedHeartbeat]

yeah, the insulation on the wiring might be pretty brittle. For no more than what a harness cost I would go ahead and replace it with the sensors, that way you get new soft seals.