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Guest Message by DevFuse
 

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Uncracked knock sensor=OK??


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9 replies to this topic

#1 brighton98

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Posted 13 August 2007 - 07:39 PM

I'm having a little cold hesitation, so the first thing I have checked is the knock sensor. It has a little rust around the bottom edge, but all metal and plastic are uncracked. Can I assume this is OK and look elsewhere, like replacing the old (non-OEM) wires, or could it still be bad?? BTW-no codes. Thanks.

#2 Reveeen

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Posted 13 August 2007 - 08:11 PM

If you are not getting a knock sensor failure code it is fairly safe to assume it is ok.
Now, there has been some mention of the knock sensors confusing piston slap with pinging and retarding the timing, as the frequency of sound generated by both conditions is different, and your knock sensor shouldn't "see" piston slap, I can't comment on the accuracy of such claims. Maybe for piece of mind re-locating the knock sensor is an idea (remembering that it must be grounded at the through bolt or it will throw a code), and also keeping in mind that you are defeating the purpose of the knock sensor by re-locating it.
Of course, seeing where it is, $200 worth of tools is handy for this job, not to mention fingers with 6 joints.
Probably easier is temporarily unplugging the knock sensor and subbing a 520K ohm resistor in it's place electrically (to ground), this will satisfy your computer, and for about 5 cents keep your tools in your tool box, not to mention totally eliminate the knock sensor as a "problem".

#3 86BRATMAN

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Posted 13 August 2007 - 08:21 PM

$200 worth of tools... For a knock sensor... :confused:

#4 Manarius

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Posted 13 August 2007 - 08:28 PM

Knock sensors on all the EJ series engines (except the EG33) are really....really easy. Rediculously easy.

#5 86BRATMAN

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Posted 13 August 2007 - 08:30 PM

Knock sensors on all the EJ series engines (except the EG33) are really....really easy. Rediculously easy.


So easy it takes literally 5 minutes to change... If you take your time...

#6 ericem

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Posted 13 August 2007 - 08:38 PM

you guys are fast. Took me like 20minutes the first time. Mainly because I didn't know where it was LOL.

#7 JohnVT

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Posted 13 August 2007 - 09:32 PM

you guys are fast. Took me like 20minutes the first time. Mainly because I didn't know where it was LOL.

Took me less than 20, but a little more than 5. Not counting the time spent here reading how to do it, and that I should ignore the Haynes instructions telling you to remove the intake manifold to get to it :eek: .
All in all, very easy.

#8 floater

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Posted 13 August 2007 - 09:36 PM

the hardest thing other then locating it was putting that bolt through the hole of the sensor and putting it back in the hole and tightening it. My trick was to use a small flashight to see, put the bolt into the socket, put some duct tape around the the bolt/socket to keep it in the socket and tighten away.;)

#9 porcupine73

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Posted 13 August 2007 - 11:35 PM

Just because the knock sensor is not cracked does not mean it is functioning properly. You only get the knock sensor CEL code if the ECU detects a problem with the circuit.

You will not get a CEL if the knock sensor is simply overly sensitive. If the ECU thinks it is seeing knock, it will retard the timing until it thinks it stops seeing knock.

Also the mating point of the sensor to the block must be clean and free of corrosion and the mounting bolt torque must be correct.

#10 Anthenium

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Posted 14 August 2007 - 09:09 AM

So easy it takes literally 5 minutes to change... If you take your time...


It took me 20. 5 to find it, and get it off(I cleaned the mating surfaces as well.), 10 to go get the new one, and 5 to put it back on, which included drinking a Beer, and clearing the code!:banana:

Tools included 2 6" 3/8 extensions, socket, and rachet...Injuries were a scraped knuckle, and few WARM moments putting the bolt back in. Shoulda drank the beer while the engine cooled...:cool:

Fat Tony




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