Knock sensors

[992dr]

A few weeks ago my cel came on and it was for both knock sensors. The guy at Advanced said that's not very common for both of them to pop up at once. He cleared it and said if it comes on again, stop by.

It popped up again Thursday and this time its for bank 2 knock sensor. Had him clear it and said. If it comes on again and its the same one, I'll replace it.

How often to knock sensors go?

Should I just replace both of them?

How long do they typically last?

I typically run 87 and add Techron or Lucas treatment, should I run a few tanks of a higher octane instead? Would that help? A buddy of mine brought it up.

My Tahoe has about 220k miles and has run fine.

Thanks

 

[Tonyrodz]

Knock sensors are typical for the nbs. I guess it's kind of a design flaw. Water collects under the intake and submerges the sensors, so they corrode and eventually go bad. Best to replace both along with the Dorman knock sensor harness, those also get a little brittle. There's a way to sort of build a "dam" using rtv to divert the water getting into the sensors and ruining them again. Hopefully someone else will chime in and explain the process a little better.

 

[992dr]

Thanks Tony,

Are the sensors on the top?
Its a Gen IV, wasn't sure if they were on the top or on the sides.

 

[aces-n-eights]

I have an '06, but i'm sure the engines are very similar. I replaced the knock sensors about a year ago and if i can do it anyone can...OK, maybe not my brother in law, but not too hard.. Time consuming but not too hard.

There are several youtube videos on how to do the repair. Basically there is a lot of "taking off stuff" to get to the sensors which are under the intake manifold.

Here's a pic of the new versus what came out of my engine...

 

[bottomline2000]

Knock sensors for genIV engines are in a different location and habe a different valley tray so the water issue should not be the problem. They are on the side of the block. If you are experiencing problems with both there may be a bigger problem. The cam sensor is also on the front plate so look for it and if there your knock sensors should be on the side of the block.

http://www.superchevy.com/how-to/engines-drivetrain/1603-ls-engine-tips-gen-iii-vs-iv/

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[Tonyrodz]

Thanks Tony,

Are the sensors on the top?
Its a Gen IV, wasn't sure if they were on the top or on the sides.

Sorry man, I didn't realize it was an nnbs. Didn't mean to give you bad info.

 

[992dr]

CEL came on again a little while ago. Bank 2 again grrr.

I have an '06, but i'm sure the engines are very similar. I replaced the knock sensors about a year ago and if i can do it anyone can...OK, maybe not my brother in law, but not too hard.. Time consuming but not too hard.

There are several youtube videos on how to do the repair. Basically there is a lot of "taking off stuff" to get to the sensors which are under the intake manifold.

Here's a pic of the new versus what came out of my engine...

Hahaha, that's how I feel about my brother, he cant change a flat tire.
I believe yours is a Gen III, only because you said they were under the intake manifold
Thanks for the info, I appreciate it.

Knock sensors for genIV engines are in a different location and habe a different valley tray so the water issue should not be the problem. They are on the side of the block. If you are experiencing problems with both there may be a bigger problem. The cam sensor is also on the front plate so look for it and if there your knock sensors should be on the side of the block.

http://www.superchevy.com/how-to/engines-drivetrain/1603-ls-engine-tips-gen-iii-vs-iv/

Sent from my SAMSUNG-SM-T377A using Tapatalk

Thanks for the info and link. I'll check it out tonight.
So far, it only through a code for both once. Last week it came on and again today, both for bank 2.
I'll do a little more research tonight and see what comes up. Otherwise, I'll more than likely replace both.
Should I look into replacing anything else?

Sorry man, I didn't realize it was an nnbs. Didn't mean to give you bad info.

No worries my friend and no need to be sorry. I appreciate you dropping in

 

[992dr]

CEL came on yesterday, again bank 2. Had it cleared.

This morning came back on, yay.

I'll be ordering some new knock sensors tonight.

 

[bottomline2000]

CEL came on yesterday, again bank 2. Had it cleared.

This morning came back on, yay.

I'll be ordering some new knock sensors tonight.

What was the exact code it's throwing?

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[Chris05]

If both knock sensors are throwing a code, can they cause a reduction in engine power? I have an 05 Tahoe with a 5.3 that is struggling to get out of its own way right now, I’ve deleted cats and changed plugs, replaced the purge flow solenoid as well. With none of these helping. It’s throwing so many codes I’m not sure where to go next.