knock sensor
mechcanic changed harmonic balancer and now check engine light came on and indicates knock sensor
My car has 165000 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
Hello. To understand what is going on, lets discuss these two components and how they work. Harmonic balancers are essentially vibration dampeners in the engine that counteract the torque caused vibrations coming from the crankshaft. Every time the combustion cycle takes place this torque vibration is amplified a little, then when you have thousands of cycles going per minute, you can image how this vibration can add up. Now on the other hand, we have knock sensors which are supposed to sense any extra knock caused by spark timing. If extra knock is sensed, then the computer retards the spark voltage and attempts to compensate to help preserve the engine. So, if the harmonic balancer is loose, installed incorrectly, or faulty to begin with the crankshafts vibrations are not being dampened. These vibrations are what is causing the issue with the knock sensors. They are not able to solve the issue (because it is unrelated to their system), and are telling you that there is something wrong. Have the harmonic balancer tested and reinstalled as needed to make sure it is functioning as needed.
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FAULTY KNOCK SENSOR: SYMPTOMS
Engine warning light comes on. Error code is stored. Reduced engine power. Increased fuel consumption.
The knock sensor is located on the outside of the engine block. It is intended to record knocking noise in all engine operating states in order to prevent engine damage. The knock sensor “listens out for” the structure-borne vibrations from the engine block and converts these into electrical voltage signals.
If the knock sensor fails, the PCM may not recognize or correct spark knock. As a result, you may hear a metallic pinging noise from the engine. The noise is often most noticeable when the engine is under a heavy load.
The engine knock sensor alerts the driver that knocking has been detected inside the engine.
The knock sensor could be missing entirely and it would not prevent your car from starting. You can drive with a bad knock sensor, but it could have adverse long term effects on your engine if there is a lot of pre-ignition, and the car will not pass most state inspections until it is fixed.
If the knock sensor is not working then the engine could start pinging without the computer being able to detect it. This pinging can cause the combustion process to burn or blow holes in the pistons.
Your car`s knock sensor is located on the engine block, intake manifold, or cylinder head and detects abnormal vibrations caused by engine detonation.
Most often, your knock sensor will start malfunctioning due to faulty or bad connections. Sensors in your vehicle are sensitive, so any excessive vibration, movement from the wires, or other issues can cause a sensor to become disconnected.
Genuine Honda 30530-PPL-A01 Knock Sensor, This is the official Genuine Honda Parts replacement part for your vehicle.
This is dangerous because it increases air pressure in the cylinder more than is normal. This can puncture the pistons in the engine and cause extensive damage in some situations. The knock sensor of a car is a small, cylindrical part that detects irregularities and malfunctions in the combustion of the engine.
A knock sensor can last for 150,000 miles or more, but it could fail sooner for any number of reasons. If you notice any symptoms that you need knock sensor replacement, you should get it fixed as soon as possible, whether you have a shop fix it or do it yourself.
The knock sensor detects vibrations that come from a knock or an irregularity in combustion and send a signal to the engine control computer, which then adjusts timing to correct the knock.
Diagnostic trouble code (DTC) P0325 stands for Knock Sensor Malfunction (Sensor 1, Bank 1). The code indicates your car`s primary computer, which is often referred to as the powertrain control module (PCM), perceives a problem with the knock sensor or its circuit.
This is a self-generating piezoelectric design that requires no power to the sensor.
Typical 2 wire knock sensor circuit with Bias Voltage – 2.5V with sensor connected. (other wire ground). This sensor has a flat frequency response over the 5 to 18 kHz range.
A failed knock sensor will register a trouble code and illuminate the Check Engine lamp (CEL), although some engines will require multiple failure cycles before storing a code.
In most cases, there is little to clean and reuse as when a sensor goes out of calibration from wear or mechanical damage, or fails due to heat damage, the only repair is to replace them.
A failed knock sensor will register a trouble code and illuminate the Check Engine lamp (CEL), although some engines will require multiple failure cycles before storing a code.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Knock Sensor + Wiring Harness installation cost? Will YourMechanic install parts if I provide them?
ANSWER : Hello. Yes we will install parts that are provided by you but doing so will void our warranty. You will also be charged for the technicians time if the part you provide does not fit properly. After we install the parts if the condition returns we will come back out and inspect the vehicle. If the issue is not related to the service we performed you will be charged an inspection fee but if it is related we would turn that over to our warranty claims department. The harness is something that our parts department can obtain for you when you’re ready to schedule your next appointment. I will ask our customer service department to send you a quote for the knock sensor installation and they should be able to get a price for that harness too. Thank you for choosing YourMechanic!
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Having trouble trying to locate my knock sensor. It’s throwing a code for it. 1,2,4,5,6 cylinder misfires
ANSWER : As you may know a knock sensor may fail for any of the following reasons:
The knock sensor is faulty and needs to be replaced
There is a wiring open/short/fault in the knock sensor circuit
The PCM/ECM has failed
Any of the above could potentially cause a misfire. The knock sensor should be located under the intake manifold between cylinders #1 and 2.
If you need assistance with this, consider YourMechanic, as one of our mobile technicians can come to your home to diagnose the misfire firsthand and help you fix it accordingly.
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I have a bad knock sensor. Is it worth replacing?
ANSWER : Hello. Yes, you are correct – the P0325 is indicative of a failed knock sensor (or the knock sensor wiring). I think it is a rare circumstance where you would not want to make this repair. It is straightforward and relatively inexpensive to repair, would improve engine power and efficiency, and might also prevent poor fuel mixture issues that could clog your catalytic converter. It is an important part of your engines efficient and clean operation. I recommend having a knock sensor replacement service completed by a mobile, professional mechanic, such as one from YourMechanic. The choice is ultimately yours, but this repair could help extend the life of your car.
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Knock Sensor issue
ANSWER : The sensors are doing their job and telling you there is a knock in the engine. Even though it may seem like the sound went away, you may not be able to hear it when you drive but the sensors can. The knock sensors are designed to produce a voltage when they hear a knock noise from the engine internal parts.
You need to have the noise you hear checked by a mechanic to see what is the cause and what needs to be done in order to fix it.
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I have a bad oxygen sensor, bad power steering sensor, and a bad cam shaft sensor? Should I replace any of them?
ANSWER : When you say you have three bad sensors I can only assume you have had them tested and the end result is three bad sensors. If they tested bad then they should be replaced. The power steering sensor senses the load of the steering on the engine so it can raise the idle during parking maneuvers. The O2 sensor is used for fuel control and it may effect engine power and fuel mileage. The camshaft sensor cay cause no starts, engine running problems and all three will turn on the check engine light.
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I did replace the heater core and two sensor the crank sensor and camshaft sensor it didn’t work can it be the computer
ANSWER : If the check engine light is on, what kind of codes is the system detecting? Do you have spark at the plugs? If you have spark, does spritzing some starter fluid give you a momentary startup? If so, there is a fuel issue. More symptoms and information on the car’s behavior before and after the parts you replaced would be very helpful. At this point, I would recommend an inspection from YourMechanic.com to diagnose this car starting problem, get an accurate assessment of damage and cost estimate for repairs. YourMechanic.com can dispatch a mobile, professional mechanic to your location to help you get your car up and working again.
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Water gauge showing red hot, but engine is not hot…..is it a sensor if so which one?
ANSWER : Hi there. There are several coolant sensors for the supra; ac, fan, ecu, and gauge. It sounds like you may need the gauge sensor, but a wire harness or gauge issue could also be the culprit. This is a single wire sensor and may match the ac coolant sensor in the same vicinity. The two sensors have different colors on the top with the gauge usually having an orange or red color. It seems like the sensor has shorted internally and is causing the gauge to read improperly. I suggest having a qualified technician perform an inspection to determine if the sensor is faulty and avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a temperature gauge is maxed out inspection.
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Car won’t accelerate past 25 mph and makes deep noise when you try too replaced o2 sensor maf sensor/ throttle body does rattle
ANSWER : Hi there. It is quite possible that your car has entered what we call a fail safe or "limp mode" due to an error code being activated and stored in the ECU. This will occur when the ECU or a sensor detects a mechanical or electrical fault on one or several fuel, ignition, cooling or powertrain systems. It’s designed to allow you to safely "limp" your car to a repair facility or home so a professional mobile mechanic can complete a car is slow to accelerate inspection and determine the right course of action. It is also possible that this issue is caused by a loose vacuum line or other component like the throttle position sensor.
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