Knock sensor location

[Jokester]

Can anyone tell me where the knock sensors are located on a 2005 Avalanche 1500 w/ 5.3L? There are apparently two of them.

Mechanic claims he has to remove a manifold to get to it.  Don't know if he means intake or exhaust.  It's my son's vehicle 1500 miles away.

Autozone has an online component locator, but this vehicle isn't one they list.

Thanks if you can help.

.bjb

[wayne petty]

detonation sensors are usually buried down under the intake manifold...

http://parts.nalleygmc.com/images/parts/gm/fullsize/041011TC00-682.JPG

hidden down in the holes in the cam lifter cover in the right image...

are you sure they are bad..

please check the end of the crank sensor first..  there have been issues of the tip of the sensor striking the crank reluctor.. causing all kinds of problems..

there are spacer kits to shim a new one back ever so slightly.. the impacts on the tip of the sensor are really hard on the ceramic magnets embedded in the sensor causing weird patterns..



with a scan tool looking at the amount of spark retard..   tap on the block with a LONG thin screw driver..  the factory on cast iron motors used something like a 5/16" steel ball on the end of a solid antenna whip in the camaro factory to verify before installation that the detonation sensors are actually working..

my OTC monitor does not cover OBD 2 newer than 98 in other than generic.. and my HF98614 i have not tried to plug into one of those to see what displays..

[Jokester]

Thanks Wayne,  suspicions confirmed.

No, not sure it's bad.  Son had it towed in.  The mechanic said one coil wire had fallen out.  Whether that's enough to make it ping or not remains to be seen.  They're going to fix the coil and have him bring it back in a couple of weeks for the knock sensors.  I don't know if the shop is that busy or if they don't have the parts.  

I'm hoping that fixing the coil and clearing the codes will take care of it.

Thanks for the info.

.bjb