engine knock sensor

**binnie2424** · 12-28-2009, 07:17 PM

Where do I find the knock sensor? How do I replace it?
Thanks

**Y2KPewterSS** · 12-28-2009, 07:38 PM

Remove the intake manifold, and there is a valley cover between the heads. The knock sensors are located down inside that valley cover.

**MonteLS1** · 12-28-2009, 08:15 PM

Yes they are under the intake plenum, pretty straight forward job, 9 time out of 10 the rear one will have rust and corrosion around it, as for some reason water gets in around it, make sure you buy new a new knock sensor harness as well, as it gets corroded also, it's very cheap and readily available from GM also, use GM sensors also, saves headaches sometimes.

**Sic vett** · 12-29-2009, 01:42 PM

What is the purpose of knock sensor

**0rion** · 12-29-2009, 01:43 PM

Originally Posted by Sic vett

What is the purpose of knock sensor

detects knock or pre-detonation and pulls timing

**Hi-Po** · 12-29-2009, 05:27 PM

Use some small (skinny) plyers to remove them. Having an asortment of plyers helps alot.

About halfway down, there are some nice pictures on exactly this.

http://www.ls1howto.com/index.php?article=18

**joedude02** · 12-29-2009, 06:18 PM

don't mean to thread jack, but is it common for the knock sensors to act up from time to time? my car seems to have a good day and a bad day if you know what i mean. i can feel the timing retard on the bad days.

**joedude02** · 12-30-2009, 06:28 PM

ttt

**0rion** · 12-30-2009, 06:31 PM

not to my knowledge....do you wash the engine with water? That's the number 1 killer of knock sensors. You have to first log the car to make sure you're actually getting timing pulled then you need to verify that it's false knock and not real knock. Couple things can cause knock.....too lean, too much timing, build up of carbon ect. ect. The first step is to log it though and see if you're actually getting knock retard then go from there.

**joedude02** · 12-30-2009, 06:41 PM

i have to admit that i do rinse the engine off with water after engine brite cleaning. guess i need to replace them. 70k and i just started stompin on it.

**SOMbitch** · 01-01-2010, 09:19 AM

Originally Posted by joedude02

i have to admit that i do rinse the engine off with water after engine brite cleaning. guess i need to replace them. 70k and i just started stompin on it.

I would verify the pcm is pulling timing due to false knock before I go through that trouble......

**SteveCZ28** · 01-01-2010, 09:38 AM

not to high jack but im having issues with my knock sensiors too...mine is bank 2 low input...i have rinsed my engine off in the past. but its been a good 6months since i last washed it and got this code. at first it would go on and off intermittently, but now its constantly on, and gas mileage is suffereing for it....so i take it my ecu is throwing a ton of timing at it compensating for the low input??