Knock sensor on a 3.1

[RareGMFan]

How hard are they to get to, and what tools will I need (size of socket, etc)? Any special techniques to make the process go easier/smoother? I assume rocking the motor forward with the dogbones removed will help a bit.

[GutlessSupreme]

I'd imagine pulling the alternator and bracket would help a lot too. I never tried pulling the sensor, but trust me that it'll be worth the 5 minutes to pull the alt & bracket for all the extra room you'll have back there.

[GP1138]

If you can kneel on top of the intake plenum (nice on the 3.1 since it's flat, just put something to cushion it on top) and remove the alt you should have plenty of room, it's sticking out from the block, and it spins out (righty tighty lefty loosey). Literally should take about a half hour, you'll spend more time removing the alt and finding the sensor. You could remove it with a socket, but I was able to just use my hand (IIRC) on my old 3.1 Lumi.

[5speedz34]

but I was able to just use my hand (IIRC) on my old 3.1 Lumi.

 

:shock: :shock:

 

Yeah, it should be like a 17-19mm socket.

[GP1138]

but I was able to just use my hand (IIRC) on my old 3.1 Lumi.

 

:shock: :shock:

 

Yeah, it should be like a 17-19mm socket.

 

I am a walking, talking oil filter wrench. Haven't met one yet I couldn't just twist off!

[stockgp]

GP1138 wrote:

but I was able to just use my hand (IIRC) on my old 3.1 Lumi.

 

 

you must have one hell of a g.i. joe kung-fu grip. i don't think it should unscrew that easily

[Jcrow]

I think you can get to it from the bottom - between engine and trans. A pair of slip joint pliers should loosen it.

[Brian P]

18mm IIRC, yes it helps to remove the alternator. Also the connector comes off by "squeezing" it and pulling. You shouldn't be able to remove it by hand, as I think GM wants it torqued to 30 lb/ft

[Guest TurboSedan]

i get mine from under the car too, but then again having a 5-speed gives you a ton more room

[stockgp]

18mm IIRC, yes it helps to remove the alternator. Also the connector comes off by "squeezing" it and pulling. You shouldn't be able to remove it by hand, as I think GM wants it torqued to 30 lb/ft

 

that's a negative. i would've figured more, but apparently gm only wants it to be torqued to 14 lb/ft

[Brian P]

hmm no doubt. I need to add more lube to the gears in my head

[RareGMFan]

Thanks for all the info, guys. So does anyone know if getting at it from the bottom would be easier, or from the top with the alt & bracket removed, and the engine tilted. I don't want to start disassembling a lot of stuff if I don't have to because the management at my apartments will have my hide, but if it's easier......I'll risk it.

[5speedz34]

Thanks for all the info, guys. So does anyone know if getting at it from the bottom would be easier, or from the top with the alt & bracket removed, and the engine tilted. I don't want to start disassembling a lot of stuff if I don't have to because the management at my apartments will have my hide, but if it's easier......I'll risk it.

 

Honestly, IMO from the top would be easier since you an auto. My friend did his on the 4t60e car and he said it was a huge bitch granted this was a 3.4.

 

I would go from the top, plus if you go from the bottom you have to jack it up and all that shit.

[RareGMFan]

Alrighty, thanks. I will try to attack it this weekend.

[Jeff M]

18mm IIRC, yes it helps to remove the alternator. Also the connector comes off by "squeezing" it and pulling. You shouldn't be able to remove it by hand, as I think GM wants it torqued to 30 lb/ft

 

that's a negative. i would've figured more, but apparently gm only wants it to be torqued to 14 lb/ft

 

Correct, only snug=14 lb/ft :!:. Read something a while back that told the importance, don't remember the details now other than it messes up the sensor and its reading so just know its what ya need to do 8).

 

Jeff M