WTB knock sensors + questions!
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WTB knock sensors + questions! I have code PO327 - I cleaned the engine bay last weekend and I'm guessing that I performed the "water under the intake" mod, which obviously leads to the "replace the knock sensors" mod.
Knock sensors:
Tried O'Reilly ($47 not in stock) & Autozone ($35 not in stock). Is this a dealer item? And how much?
Should I replace the wire pigtail? If so, is that a dealer item?
Should I use the GM intake gaskets or buy aftermarket? I'm assuming that the gaskets have to be replaced and not re-used.
I'm up to date on the LS1 How To web page for the intake manifold, but does anyone have any tips or tricks that will make my life easier?
Thanks for any help!
Knock sensors:
Tried O'Reilly ($47 not in stock) & Autozone ($35 not in stock). Is this a dealer item? And how much?
Should I replace the wire pigtail? If so, is that a dealer item?
Should I use the GM intake gaskets or buy aftermarket? I'm assuming that the gaskets have to be replaced and not re-used.
I'm up to date on the LS1 How To web page for the intake manifold, but does anyone have any tips or tricks that will make my life easier?
Thanks for any help!
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Todd, knock sensors are pretty common at a dealership. They cost about $30 to $40 if I remember correctly. I would definitely replace the wire. I've found that the dealers had to order the wire, takes a day.
You don't need intake gaskets.
The manifold is pretty straight forward. One good tip is that when you remove the fuel rails, don't disconnect the fuel line, just fold the rails over to the right (driver's side). When you reinstall the intake, don't forget the little vacuum line in the back. Bolting it back down, use the correct pattern as shown in the manual. When you reinstall the KS wire, be careful to route it to the left but not so far left that the intake crushes it when you bolt it back down. Use silcone RTV (red) around the knock sensors to block water from getting in there in the future. Also, remove the foam square under the intake because it wicks water up under the intake. That's all I can think of. Any problems just post questions.
Good luck!!
You don't need intake gaskets.
The manifold is pretty straight forward. One good tip is that when you remove the fuel rails, don't disconnect the fuel line, just fold the rails over to the right (driver's side). When you reinstall the intake, don't forget the little vacuum line in the back. Bolting it back down, use the correct pattern as shown in the manual. When you reinstall the KS wire, be careful to route it to the left but not so far left that the intake crushes it when you bolt it back down. Use silcone RTV (red) around the knock sensors to block water from getting in there in the future. Also, remove the foam square under the intake because it wicks water up under the intake. That's all I can think of. Any problems just post questions.
Good luck!!
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I'll try to find the part # tomorrow... i've been through this before 
https://ls1tech.com/forums/showthrea...ighlight=P0327
in my case I bought new sensors and didn't need them
https://ls1tech.com/forums/showthrea...ighlight=P0327
in my case I bought new sensors and didn't need them
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Thanks for the responses 
I saw the GM TSB on the Corvette website (another thread here had posted the link) and saw how the RTV "dam" was recommended. They showed it as being NOT a complete circle around the sensor, and if I remember right they said to only dam up the rear one and to only remove the rear foam piece.
Anyone remove both foam pieces and dam up both senors? Oh, and does the "opening" in the "dam" go to the rear or the front of the car?
That's a good thing, I think! I'm hoping for the same outcome....although if the sensors aren't the problem, finding out what's setting codes is going to be a pain in my wallet!!
Originally Posted by Predator
Use silcone RTV (red) around the knock sensors to block water from getting in there in the future. Also, remove the foam square under the intake because it wicks water up under the intake.
Anyone remove both foam pieces and dam up both senors? Oh, and does the "opening" in the "dam" go to the rear or the front of the car?
Originally Posted by horist
in my case I bought new sensors and didn't need them
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Todd, if you're getting P0327 you can be 99% sure that it's a shorted KS, especially since you said you just washed your engine.
Remove all and any foam under the intake, all it does is hold water.
Make a "dam" on both sensors. The opening of the dam should be to the rear (toward the firewall). Logically, when you pull away with the car, the forward momentum will cause any water to flow off the valley and out the rear opening, between the intake and the valley.
Remove all and any foam under the intake, all it does is hold water.
Make a "dam" on both sensors. The opening of the dam should be to the rear (toward the firewall). Logically, when you pull away with the car, the forward momentum will cause any water to flow off the valley and out the rear opening, between the intake and the valley.
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Originally Posted by Predator
Todd, if you're getting P0327 you can be 99% sure that it's a shorted KS, especially since you said you just washed your engine.
Remove all and any foam under the intake, all it does is hold water.
Make a "dam" on both sensors. The opening of the dam should be to the rear (toward the firewall). Logically, when you pull away with the car, the forward momentum will cause any water to flow off the valley and out the rear opening, between the intake and the valley.
Remove all and any foam under the intake, all it does is hold water.
Make a "dam" on both sensors. The opening of the dam should be to the rear (toward the firewall). Logically, when you pull away with the car, the forward momentum will cause any water to flow off the valley and out the rear opening, between the intake and the valley.
Just got back from the dealer - got 2 sensors and 1 pigtail just in case (can return unused parts!!) Got some RTV to dam everything up. About to go out and yank the intake.
Cost me $55 each for the sensors.....GOTTA find a hookup with a parts guy for the next time!!!
Thanks for the help everyone
Will post up when I get done. I'm starting now, so I should be done about Tuesday, the way things work for me!! 
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Originally Posted by Predator
One good tip is that when you remove the fuel rails, don't disconnect the fuel line, just fold the rails over to the right (driver's side).
Ahaaa!! Fiddled with the fuel line for a few minutes and thought....Better check the tip section again!!
And yes, I started a bit over 2 hours ago.....taking my time - last time I messed with an intake (about 15 years ago) I cracked it and it cost me some serious $$$$.
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Originally Posted by Predator
Cool Todd, sounds like it's going great. Taking your time is always smart, and a lot more fun too.
On the A4 the tranny dipstick is DIRECTLY above the last two bolts on the pass. side.Going to try to get the bolts high enough to get the intake to slide forward.
May have to loosen the damn tube thought
Just searched for tips on that bit, but no luck....
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Originally Posted by Predator
Just wanted to mention that when I said that the sensors were between $30 and $40, that was from gmpartsdirect.com, not a dealer. I remember now.
No big thing - I expected them to be more than the highest auto parts store listed them for (I was bummed the auto parts store didn't have them, though!)
Front knock sensor corroded - pocket it sits in was full of water and some whitish goopy looking stuff.
Rear knock sensor looks brand new - no water in that pocket but there was oil in it. This seems bad to me. Actually I'm thinking this seems kind of really bad. But I don't know for sure. Hopefully someone can post up and tell me for sure.
EDIT - Found this in a search - sorry - should have searched first!!
Originally Posted by xssive
There are some seals that are around the bottom of the knock sensor mounting bosses. Remove the valley cover and replace the seals. They are a very hard rubber that gets brittle over time...
Edit again- can I just RTV around those if I take the valley cover off? And can I re-use the valley cover gasket?
Last edited by 01ArcticSS; Apr 16, 2005 at 04:53 PM.
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I wouldn't worry about it. Just replace the sensors, wire, and do the RTV thing. You should be all set.
I also wouldn't worry about those seals under the valley cover although it wouldn't hurt to have a look at them. Your call.
It's always a good idea to use new gaskets.
I also wouldn't worry about those seals under the valley cover although it wouldn't hurt to have a look at them. Your call.
It's always a good idea to use new gaskets.
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It's done. Complete.
Yeah, it took me five or six times longer than I wanted it to, and probably five or six times longer than it would have taken most of you, but when I turned the key and the car started the first time I wanted to cheer like I personally won the Superbowl all by myself with a 1 man team!
:
:d 
Thanks for the help Predator & xssive & horist and everyone else whose threads came up on a search.
Oh, and the oil in the rear sensor well was interesting. Pulled the valley cover off and the seal did not come out with the cover. It just plain wasn't in place. So I had to massage it gently with channel locks and whack it back in with a rubber mallet.
Yeah, it took me five or six times longer than I wanted it to, and probably five or six times longer than it would have taken most of you, but when I turned the key and the car started the first time I wanted to cheer like I personally won the Superbowl all by myself with a 1 man team!
::d Thanks for the help Predator & xssive & horist and everyone else whose threads came up on a search.
Oh, and the oil in the rear sensor well was interesting. Pulled the valley cover off and the seal did not come out with the cover. It just plain wasn't in place. So I had to massage it gently with channel locks and whack it back in with a rubber mallet.
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Congrats Todd!!
I know I felt great when I finished mine. The coolest, though, was no more KS codes, and no more performance degradation.
Also, I'm a lot more careful when I wash my engine now. I use a light mist, and I don't even spray in the back anymore.
I know I felt great when I finished mine. The coolest, though, was no more KS codes, and no more performance degradation.
Also, I'm a lot more careful when I wash my engine now. I use a light mist, and I don't even spray in the back anymore.
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I actually started the car last night - 12:39 AM. Let it idle for about 15 minutes, gave it a bit of gas - like 1500 rpms - and it dropped down to like 200 rpms. I did this a few times to let it "learn" how to NOT drop down that far.
I REALLY wanted to drive it last night but if it died on me she would NOT have been happy if I called at 1 AM.
This morning I actually was able to control myself and did the lawn work before I drove it - just got back from driving it and it runs nice!!
If someone happens across this thread in the future while searching for info on the knock sensor replacement and needs any info/advice/encouragement drop me a PM if I don't happen across your thread - I also have a bunch of pictures I took along the way. Keep in mind, however, I'm no expert - I just managed to get through with help of others on the board and with my Haynes manual and with LS1HowTo.
Thanks again!!
I REALLY wanted to drive it last night but if it died on me she would NOT have been happy if I called at 1 AM.
This morning I actually was able to control myself and did the lawn work before I drove it - just got back from driving it and it runs nice!!
If someone happens across this thread in the future while searching for info on the knock sensor replacement and needs any info/advice/encouragement drop me a PM if I don't happen across your thread - I also have a bunch of pictures I took along the way. Keep in mind, however, I'm no expert - I just managed to get through with help of others on the board and with my Haynes manual and with LS1HowTo.
Thanks again!!
