if your CEL comes on and you get the Knock Sensor code.. remove the knock sensor and clean the bottom of it (where it grounds through the block) with a wire brush and get all of the rust off of it. I unfortunately just bought a new knock sensor and installed it, i no longer get the code, but i took a volt-meter to the old one, and once i cleaned it off, it read within the correct range... so hopefully this will save some of you 60 bucks or so.. i wish i knew this before i bought mine..

Also if anyone wants to buy my old KS... the plastic is cracked but it still works.. i'd sell it for real cheap. PM me.

 

I've got 200k+ and I am still on my original knock sensor. Not looking forward to having to change that after these lovely Ohio winters.

 

You are incorrect. When the old knock sensor gets hot it will be out of the correct range.

 

heat from the block will have VERY LITTLE or no effect on the Ohm reading of the knock sensor.. the heat should not change the resistance of the KS... what is your basis for this statement?

 

Experience.

I had the same feeling after I changed mine and tested the old one. Then, after reading on the .org, I found many others had the same situation happen. IIRC, the expansion of the materials due to the heat causes the malfunction. I have no doubt that your ohm reading while cold is correct, but it is when that sucker gets hot that it malfunctions.

Also, the cracked housing you mentioned is also a tell-tale sign.

 

I pulled mine out to replace it and found the housing was cracked also. The readings I got from it off my multi meter were all screwy before I found out it was cracked so it was due.

 

I have replaced more than several of these knock sensors on customer cars.

One of my things I like to do is check the old sensor with a Fluke meter to see if I can determine if it is indeed bad.

About 1 in 5 old sensors have no physical damage apparent, and also have a good reading on the ohmmeter.

But there is really no good way to determine just how they perform when hot and under duress.