Hey guys,
Well, it's time to finally get under the hood and replace my knock sensor. I've been busy with all the maintenence items so far... Anyways, my question is this -- by using a flex joint and an extension to torque the bolt, will my torque wrench be inaccurate? I want to torque it to spec, and I just can't seem to believe that the torque readings from the bolt will transfer to the wrench with any variations. How did you guys address this?

Lou

On a similiar note, When I was replacing my sparkplugs, it seemed that I was torquing (sp?) forever, and my wrench was not "ticking" like it should have been. I had it set to 18 ft-lbs, and I couldn't even turn the wrench anymore (it's a 3/8 drive wrench). Is it the flex of the extension that throws off the torque wrench setting?

 

When working through a flex joint, the applied axial torque to the bolt will be significantly less than what the torque wrench is applying. The greater the angle difference between the axis of the bolt and the turning axis of the torque wrench, the greater the difference will be.

Torque (or moment) is a vector quantity. To change its direction (ie. through a flex joint) an external torque must be applied.

You will find a portion of the torque you apply is trying to rotate the socket off of the bolt instead of turning it. You actually have to apply a downward force to prevent this from happening as you tighten the bolt.

I do not use a torque wrench for a knock sensor or spark plugs. The only things I tend to use a torque wrench on are for parts where a certain degree of clamping force is required to prevent separation from externally applied loads (ie, cylinder head, conn rods, crank bearing caps. etc.)

 

Yeah, Just Get It Tight, U Should Be Ok

 

I wasnt worried with torquing it to spec, I just tightened it back down, but not too tight. its been fine (havent gotten a call from my brother yet)

 

If you don't use a torque wrench for the knock sensor then how much of turn should you go on the wrench after you hand tight it snug? A quatre turn, half turn. I know for spark plugs once you snug tight you do a quatre turn, but not sure about for knock sensor since it so sensative I want to make sure I tight it down correctly. I heard not tight enough no good, too tight no good too.

 

I wouldn't worry about torquing it. Just use a 22mm wrench and make it tight. I also wouldn't change your O2s "just 'cuz". I'd only change them if you get a code.


I use a smaller in-lb torque wrench for my spark plugs.

 

Are you positive you were using a ft-lb torque wrench and not a in-lb torque wrench?

Who said anything about O2 sensors????

 

It is an in-lb wrench, but I would have had it at 216 in-lbs.

On a fairly unrelated note...this thread is OLD!! I was still in high school when I made this thread...going on my 4th year of college this fall

 

Maybe you were confused back in 05??

Damn. Didn't even notice when the thread was started.....

FAIL for the threadbump.

 

I thought this was a modern O2 thread.... it's an old KS thread. Someone shoot me.

 

Ptatohed

 

When I tightened the knock sensor using a long extension, and a universal swivel. I used the bottom of the plenum as a pivot point and lifted up on my wrench. This applied downward force to keep the socket on the bolt. I used a small ratchet, hand tightened, and went a little less than a quarter turn more.

 

To me, the knock sensor is the ONE sensor that should be properly torqued down properly.

 

Not a chance in the world. Ever.

Mine has been doing fine for almost 4 years now (given the thread date...lol), but is there any way of ensuring proper torque without ripping the IM's off? I couldn't see a reliable, accurate way.