over tightening knock sensor

[MyBeatGSX]

Quick question, no guesses please. I over tightened my knock sensor when installing it awhile ago, I wasn't aware that it shouldn't be too tight. Now the question is, can I take it off and just put it back on to the correct torque or is it perminately broken? Does overtightening really cause false knock readings?

 

[andymoraitis]

Yes it'll cause false knock readings and yes you can remove it and re-install it to the correct torque. The knock sensor is nothing more than an electronic microphone. If it's in too tight, it'll pick up a level of excess noise in direct proportion to how much it was overtightened.

 

[steve-o_95_GST]

how do you properly torque a knock sensor with the cord in the way? Does an o2 sensor socket fit over it? I think mine may be over tightened so I want to correct it.

-Steve

 

[MyBeatGSX]

Yea that's a good point. There isn't a socket on earth that is that big and has the notch in it. I just used a huge adjustable wrench and cranked the crap out of it. Let's hope this is what's causing all my knock on the logs.

So it just hand tight and then a little turn, just like a spark plug right?

 

[dnhieu]

while we are at it lets throw in the proper torque for the knock sensor. i might beable to feel it out close enough...

 

[andymoraitis]

It's supposed to be around 17 lb/ft. About the same as a cam cap if you want reference.

 

[somdturbo]

anyone heard of a crows foot? This would work great for this purpose for the correct torque value (above^).

http://images.google.com/images?sou...2004-37,RNWG:en&q=20mm crows foot&sa=N&tab=wi

 

[steve-o_95_GST]

Ill have to stop by sears and pick a set of those up then. Now there is the matter of getting my torque wrench to fit under the inkake manifold. Good find

 

[MyBeatGSX]

Nice find Is 20mm the correct size?

 

[Auto RS T]

24mm is the 1G size. The 2G size is different. (My mistake).

Have fun fitting the torque wrench in there.

I didn't see in the manual the torque rating. Why is this?

 

[MyBeatGSX]

I have a small 3/8 drive 500 in/lb torque wrench, its less than a foot long, that should fit in there without too much issue.

Hmm, 17 ft/lb = 204 in/lb... I think that's even less than the spark plugs.... yes that's right, I torque my spark plugs, I am that anal.

 

[Kevin Jewer]

I don't see how a torque wrench can be considered accurate when used with a crows foot wrench, you change all of the geometries. I'm no dentist though.

 

[idt512]

I don't see how a torque wrench can be considered accurate when used with a crows foot wrench, you change all of the geometries. I'm no dentist though.

only altering 1 dimension, so subtract an inch for the crowfoot...it would translate to be 188.36 in/lbs or 15.69 ft/lbs

 

[RavenX]

We took the correct size socket and made our own slit just like the O2 sensor. We were out of one socket put who cares it slips in easy enough with the torque wrench

 

[MyBeatGSX]

24mm is NOT the correct size for a 2G sensor. Be careful what you say unless you're 100% sure because I just wasted $5 on a useless crow foot.

The correct size is more like 1". I used an adjustable wrench and got it back there pretty easily. Obviously I couldn't use a torque wrench, so I tried the torque wrench on another bolt to feel out 17 ft/lb and then tried to retighten the knock sensor the same.

I made 2 logs and they're much better and much more consistant. I'll post them up in my other topic later today.

 

[NHerron]

16ft lbs for a 2g turbo. 420a is 7ft lbs. From my 1997 factory service manual. I'll buy a 27mm socket to modify.

Also, the socket size is 27mm for a 2G turbo confirmed just today on a new sensor. The sensor PN for a 2g turbo is MD300670. 1G turbo is MD141510.

27mm or 1-1/16". The latter being called a sender socket (for oil pressure sender sensor) which is much easier to find than a 27mm 3/8 drive.

The attached image is from my 97 service manual.

 

[NHerron]

Edit my previous reply-

1-1/16" is actually a bit smaller than 27mm. The 1-1/16" oil sender socket I had wasn't quite big enough so I honed it out a bit bigger to fit.