Knock sensor - where is it?

[PhatBastard]

Anyone have a diagram of where the knock sensor is located ('95 SE)?

[NJMAXSELTD]

It's under the intake manifold, sort of twards the right side. It's a small black module held in place by one bolt.

[PhatBastard]

Found the knock sensor and changed it today. Took about 15 minutes...

Thanks.

[NJMAXSELTD]

Originally posted by PhatBastard
Found the knock sensor and changed it today. Took about 15 minutes...

Thanks.

15 Minutes? Your good! I've heard a few interesting stories from guys who've changed them.

Did you notice any improvement in performance yet?

[PhatBastard]

Well,I didn't include the 2 days of contemplation on what was the best way to go about it.

But after reading a couple of posts here and on the "Org", I came up with a solution that works - and works fast!

I documented the proceedure on a personal website of mine that I mess around with from time to time. If anyone is interested. Why? Who knows. Just another hobby I guess.

http://www.skippynet.com/maxima/knocksensor.htm

[PhatBastard]

Oh and I haven't noticed any improvement in performance as of yet. From my research, it looks like it takes a few days for any noticeable difference.

I've reset the ECU, so hopefully this will clear up the O2 sensor message as well.

Time will tell...

[maxgtr]

Why did you have to replace your knock sensor, cause my ecu is throwing a knock sensor code also. One more thing. how do you gain performance by replacing the sensor?

[MaxRX7]

LMAO, nice website write-up !!
I loosened the nut a bit different, and was careful of banging my hand when it came loose, because I knew what would happen


You will not gain any "performance". the only thing is your engine will not knock anymore if you use low octane gas.

when you use low octane gasoline the knock sensor retards the timing in order to prevent the "knocking" of your engine in which you might "feel" a decrease in "performance".

so from now on use 93 octane gasoline

[PhatBastard]

Originally posted by maxgtr
Why did you have to replace your knock sensor, cause my ecu is throwing a knock sensor code also. One more thing. how do you gain performance by replacing the sensor?

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My ECU was spewing the knock sensor code and a rear o2 sensor code.

Under advisement of NJMAX, I replaced the knock sensor first, in hopes that it would also clear up the o2 sensor message. So far, so good.

The check engine light has not come back on. If it doesn't come back on in the next couple of days, I'll be satisfied that both conditions have been corrected.

As far as better performance, I can't say. I've seen many opinions on this, some saying it will, some saying it won't.

My question is, if the knock sensor is bad, does the ecu still retard the engine? If it does, then maybe you'll see better performance. If not, then nothing should change. Ya think?

My next question is, why does the little bastard cost so much? A plastic doughnut with a metal bottom. Give me a break....

[PhatBastard]

Originally posted by MaxRX7
LMAO, nice website write-up !!
I loosened the nut a bit different, and was careful of banging my hand when it came loose, because I knew what would happen


You will not gain any "performance". the only thing is your engine will not knock anymore if you use low octane gas.

when you use low octane gasoline the knock sensor retards the timing in order to prevent the "knocking" of your engine in which you might "feel" a decrease in "performance".

so from now on use 93 octane gasoline

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Glad you liked it!

I just started using 92+ octane a couple of weeks a go thanks to information that I read here and on the "ORGY". I have been running the the middle grade (usually about 89) for all of these years because I swear on my granny's grave that the salesman told me to use the middle grade of gas back when I bought my Max new in May of '94, the rat bastard!

[mishmosh2000]

PhatBastard, your page is definitely the best thing going out there for KS replacement. Got the tools you suggested but when I went to loosen the screw, the damn thing just would not budge. The car was still kind of hot so maybe when cold, it'll be easier. I also sprayed some liquid wrench on it.

I too would like a definitive answer as to whether timing is retarded (or not) when the KS is bad. I get 0304 code but subjectively, I still feel like my car has good acceleration! We'll see when I change it out...

As for mid-grade: it isn't necessarily a bad thing. The KS is supposed to retard the timing so that no knocking occurs. It is not supposed to damage the KS... Even the manual says that if premium is not availble, "plus" grade will do. You just won't get optimal performance.

Update: With the car cold and the bolt sprayed with liquid wrench, all it took was a good yank and the bolt came loose. Just kept turning the socket until it was out and held the bolt with a magnet antenna. Didn't even have to stick my hand in for the removal portion!

[PhatBastard]

Glad my web page helped and your idea with the magnet is excellent.

I'll update the web page with your ideas when I return home later this week (I'm working in Atlanta for a few days).

Thanks for the info on the mid grade as well. I don't feel so guilty now!!

I'll try to remember to let you know when I update the web page.

Later.....

[MaxRX7]

Originally posted by PhatBastard


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Glad you liked it!

I just started using 92+ octane a couple of weeks a go thanks to information that I read here and on the "ORGY". I have been running the the middle grade (usually about 89) for all of these years because I swear on my granny's grave that the salesman told me to use the middle grade of gas back when I bought my Max new in May of '94, the rat bastard!

NEVER, ever listen to a salesman !!
Whenever you get a new car, read the manual, this is by far the most important thing. It clearly states to use premium gasoline.


BTW, how much did the knock sensor cost you ?

[PhatBastard]

I paid $164 & change for the sensor from Courtesy. I saw some that cost less and some that cost more. Saw a couple of different mfgs. too.

I went wth the middle of the road (cost wise) from a reliable source.

[mishmosh2000]

Am wondering if anyone has done the continuity test on their knock sensor as per Haynes Manual. Test: check the resistance of the KS. If it is infinity (no continuity), then they say to replace it. They do say that the KS has a high resistance and recommend an OHM meter with at least 10M Ohm capability.

If you do try to do this, you cannot just measure at the harness because only one of the leads (the signal one) actually goes to the KS. The case of the KS is grounded so you will have to measure with the terminals of the KS that you took out, or use the hot lead of the harness and use the ground of the car.