replace knock sensor?

Here are 2 images. There are 2 different engine codes for your vehicle. It looks like it's just mounted on the rear bulkhead.

Already answered in your other thread.

What causes the knock sensor on the truck listed above to light? The car seems to be running a little rougher. The timing belt has about 25,000 miles on it.

Hello, I'm Danny.

A knock sensor is an electrical component that can fail just like anything else after time. It is used to help aid in the engines timing to help optimize the engines performance. That is why your car is running roughly. Here is a tutorial that shows how it works:

https://www.2carpros.com/articles/how-a-knock-sensor-works

I've attached a picture below of its location.Hope this helps and thanks for using 2CarPros.
Danny-

My check engine light came on [yellow one], and I performed the code scanner and it says its the knock sensor. My shake seems to shake when warmed up at idle, just wondering if you had any ideas for what else could be causing the shaking. Thank you!

Hi there,

The knock sensor is the primary sensor to adjust the ignition timing, if it is sending a false signal to the ECU, the ECU may be setting the incorrect timing causing the idle shaking problem, change the sensor and see how it goes after that.

Mark (mhpautos)

where is the knock sensor and how do i get to the knock sensor.

located on top rear of engine

1) After a head gasket replacement I still have an ongoing emissions code? Not sure the # but I do know I get charged a lot of $$ every time I ask for them to actually fix it. They have ruled out exhaust leak replace knock censor, gas cap, etc.

2) The worst part is the fact that with the heat (especially the defrost) on the vents blow in what smells like pure exhaust. My mechanic is really reluctant to look at it other than to tell me the engine compartment is sealed and it could not be that. Anything coming in could in the heater box. The real issue is that none of these issues were there before he "fixed" it. Strange enough, this happened exactly the same way 3 years ago when I had a head gasket done (don't ask I'm a fool who does not check coolant). When defrost is on the truck is almost insufferable?

Ever heard of such a a thing? I may try to reach out the mechanic of 3 years ago who fixed it the first time, but I'm guessing he won't remember.

Thank you

Your ventilation system brings in air from outside so whatever is happening out there will be brought into the passenger compartment.

It needs to be examined more closely. By the sounds of it, you just need to try a different shop because this one is unable to resolve anything.

i need to replace the knock sensor on a 2000 nissan frontrier 6 cyl , i found the sensor for about $148 if you know how i could get it cheaper i would greatly appreciate it.

if you could give me an idea how much it will cost to replace the sensor, im not real mechanically inclined but i may be willing to replace it my self if you can provide me with any info to help me.


thank you

rob

yes i would try a salvage yard to find the part or local junk y ard you can find them dirt cheap.

Junk yard is a great place to find parts, but I wouldn't reccomend replacement parts that deal with the engine componants that are questionable unless you know what to look for.

If you do get one from a Junk yard make sure to test it prior to installing it. Chiltons manual says that if you run a Ohm reader set at 1k, and test the positive to ground on the sensor should get a reading of 100k to 600k for a good one.

I recently picked up a knock sensor for a Nissan Frontier at Pep boys for $117.00, so they are a good place to go to get parts. Now if you want them to replace it be prepared to shell out $400.00 and wait for about 4 hours. They have to remove the intake manifold to get to the sensor.

Hope this helps ya.
(I'm looking at tackling this job myself at an auto hobby shop.)

Check engine light came on and I had autozone hook it up to thecomputer ,and it said the knock sensor needed to be replaced.

The knock sensor retards the ignition timing when its senses engine detonation/pinging-like marbles being thrown in an empty tin can-

Fault codes never say to replace something. They are set in memory when the Engine Computer is not happy with the value a sensor is reporting or the circuit doesn't pass one of the continually on-going self tests. The codes are meant to direct you to the circuit or system that needs to be diagnosed, that's all. About 50 percent of the time the problem is indeed a defective sensor, but it's just as likely there is a corroded terminal in an electrical connector, a wire is rubbed through and grounding out, or it could even be nothing more than a sensor was unplugged while the ignition switch was turned on. Very often people just replace the sensor related to the code, then have the same problem. That adds to the running problem by introducing a new variable to the computer. No two sensors deliver exactly the same signals so the computer learns the characteristics of the new sensor by comparing it to other known conditions based on other sensor readings. When there's a code in memory, the computer may not learn the characteristics of the new sensor. Instead, it makes decisions based on the old sensor that it thinks is still on the engine.

The knock sensor is tuned to detect spark knock or preignition in a cylinder. When that is detected, the Engine Computer retards ignition timing to reduce that spark knock. Mechanical problems inside the engine can mimic that vibration and be falsely detected as spark knock. That can result in the ignition timing remaining retarded, which results in lower power and higher fuel consumption.

There are multiple codes that can be set related to the knock sensor. When the computer retards ignition timing, it knows the knocking should stop or decrease. If the vibration is still there due to something mechanically wrong in the engine, it may assume the knock sensor is reporting knocking when it knows there shouldn't be any, so it thinks that circuit or sensor has a problem. It COULD set the fault code when there's nothing wrong with the sensor.

Where is the Knock Sensor located on the 2000 Nissan Frontier 3.3liter V6?

It's on the top and to the rear of your engine, It's #3 in the picture. The knock sensor is NOT on top of anything except the block. It is under both the upper and lower intake manifolds.

how do i replace this sensor ?

sensor is located under the intake manifold in the center
It requires removing the upper half of the intake manifold, the injector rack, the the bottom half of the intake manifold. Remember to release the fuel pressure, drain the coolant and keep track of all your parts. While you have that off, It's best to go ahead and change the plugs.

Not sure what the problem is. truck runs great when idling, but as soon as you start to accelerate especially on interstate it misses like crazy, almost like water in the gas, but that is not the problem. I am not sure what could be causing this hooked up the code reader not sure, but it said one of the 02 sensors, and camshaft sensor and knock sensor. Not sure if any of these are the problem. Help please.

scan for codes and check fuel pressure with a gauge auto parts rent it you may need an adapter however. see link.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Hi JASON,

If you decide you would like to conduct the scan yourself here is a link to an article that features written step by step instructions and pictures explaining how to do the scan yourself, also I have included a link to our YouTube channel with a how to video on code scanning.

This is applicable even if your check engine light is not on.

Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

Thank you for visiting 2CarPros.com.

Kindest regards,
Renee
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