Question about 1995 Lexus Sc 400

1 Answer

Knock sensor repair

What is the procedure to replacing my knock sensors on this vehicle

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Lexus Expert
  • 362 Answers

The knock sensors are located in between the two cylinder heads under the intake manifold.

Posted on May 29, 2014

4 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

  • 36 Answers

SOURCE: Have a 1999 lexus es300.

If you have some common tools the knock sensors are no big deal.  If you take a lexus they will make is sound like you need to completely disassemble the engine and scare you off.
First, do you really have a problem with preignition causing real knocking due to carbon buildup, or diluted gasoline or do you have failed knock sensor(s).  Try to decarbon the engine first.
There is a technique used with water being sprayed into a warm engine intake.  This will clean up the valves and carbon buildup which can result in engine knocking.  

The job will be a couple hundred for the parts and a couple hours of your time.  After you are done, you have entitled yourself to approximately $500 in new tools for your tool chest since this is what Toyota and Lexus will charge to fix (about $1k+).

You will need to buy the following to address the knock sensors and a couple other items while you're in the neighborhood.
- 1x upper intake plenum gaskets - 2x lower intake plenum gasket - coolant bypass hose found in the same area as knock sensors - 2x knock sensors (bank1 and bank2) - short pig tail cable which connects both knock sensors to common wire harness. - toyota antifreeze  (2 gallons, if i remember correctly... when mixed to 50/50 (antifreeze/ water) you will have 4 gallons.
drain the radiator drain the front of the engine using the engine drain plug - this plug is on the front right side facing the engine, behind the right hand exhaust manifold. (this will lower antifreeze enough to avoid dumping antifreeze all over the engine later) remove the air filter box remove the connections into the throttle body remove the cable from the throttle control remove the upper air intake plenum remove the two lower air intake plenums remove the antifreeze fill port
Knock sensors will be in the valley between the lower intake plenums.  You will need to remove the rubber antifreeze bypass hose (little short hose blocking access to the knock sensors).
By the way, the reason you bought a replacement, is that if this short hose splits from normal wear, you need to spend this money and effort to reach it, so just do it now.
The little pig tail cable which connects both knock sensors to the wire harness is said to cause a big majority of the problem due to the plastic getting hot and brittle, falling off and shorting to the engine.  While in this mode the engine thinks knock is occuring and starts to retune the air fuel mixture to get rid of the knock until it goes into minimal operations mode.
After replacing the knock sensors (and tighten to torque specs), replacing pig tail cable, and reinstalling your new short by pass hose.  Replace the lower gaskets, antifreeze fill port, lower intakes, upper gasket, upper intake, air intake, air filter, reattach everything, reconnect all the rubber lines you pulled off, make sure there are no splits in the air intake passage anywhere, retighten the engine antifreeze drain plug, and the drain on the bottom of your radiator, and your done!
Don't forget the easy stuff.  Dilute the antifreeze with water and fill the radiator and overflow tub.  Run the engine for several minutes until its hot and opens the thermistat to allow antifreeze into the empty engine cavities.  Turn the engine off and get a cold one as the engine cools.  Once absolutely sure engine is cold, refill the radiator with antifreeze and refill the reserve tub.  Do this at until all the beer is gone and you are both full of antifreeze (in one form or another)..... obviously red stuff in the car, amber down the gut.

Posted on Mar 16, 2009

  • 47 Answers

SOURCE: 93 Lexus GS300 knock sensor electrical wiring?

knock sensor are atached to the short block of the engine normaly at the cylinder #1 side when the car is six cylinders

Posted on Sep 17, 2009

mecanica03
  • 881 Answers

SOURCE: 1999 rx 300 3.0 knock

remove intake manifold and air intake chamber completely, the knock sensors are located in middle of engine

Posted on Sep 07, 2010

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

2004 3.0L Escape. Where are the knock sensors located?


Knock Sensor

Print
Operation

The Knock Sensor (KS) is a tuned accelerometer on the engine which converts engine vibration to an electrical signal. The PCM uses this signal to determine the presence of engine knock and to retard spark timing.
Removal & Installation

  1. Raise and safely support the vehicle.
  2. Remove the intake manifold.
  3. Remove the bolt and the Knock Sensor (KS).
  4. To install, reverse the removal procedure and tighten mounting bolt to 15ft. lbs. (20 Nm).

Jul 21, 2015 | Ford Cars & Trucks

1 Answer

How do i change a knock sensor on a 1997 Nissan Altima?


Inspect/Test/Replace


A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark retard than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.

To replace the knock sensor:


  • Disconnect the knock sensor wiring connector.

  • Then, unscrew the sensor.

  • Remove the knock sensor.

  • Reverse the procedures to install the part.

Mar 16, 2013 | Nissan Altima Cars & Trucks

1 Answer

My knock sensor on my 2003 cadillac deville is faulted. How hard and what tools and supplies do I need to replace the knock sensor


  1. Remove the intake manifold.
  1. Disconnect the knock sensor electrical connector.
  1. Remove the knock sensor (KS).
Installation Procedure

    602292.png
    .
  1. Install the knock sensor.Tighten
    Tighten the knock sensor to 25 [n-m] (18 lb ft).
  2. Connect the knock sensor electrical connector.
  3. Reinstall the intake manifold.
    this is quite a job and i would not reccomend a novice mechanic to preform this repair book time is about two hours for this repair hope this helps

Oct 20, 2012 | Cadillac DeVille Cars & Trucks

1 Answer

Where is location knock sensor 2002 toyota sienna


Go to the link and scroll down the page to the knock sensor replacement procedure. It is very involved and if you don't know car repair leave it alone, There are 2 sensors, on for each cylinder bank.

How to fix your Toyota Sienna Knock Sensor Malfunction P0330 P0335without...

Mar 21, 2012 | 2001 Toyota Sienna

2 Answers

Remove the spark knock sencer on a 1997 dodge caravan


It depends on which engine your Caravan is equipped with. The knock sensor on the 2.4L engine is on the forward side of the engine just below the intake manifold. On the 3.3L and 3.8L engines it is on the forward side of the engine right next to the oil filter. All engines: Disconnect the electrical connector and unscrew the sensor from the engine block. Reverse procedure to install.

It should be noted that knock sensor failures are very rare on these vehicles. Most knock sensor fault codes for these engines are usually caused by mechanical problems that are creating "rattling" or "knocking" noises in the engine compartment. Things like bad pulley bearings, worn water pumps or loose timing components are most likely at fault. The knock sensor does not know the difference between vibrations caused by these type of failures and those that are caused by ignition ping. The fault code usually sets when the noise or "knock" is still present when the Powertrain Control Module (PCM) has retarded ignition timing as far as possible. If any knocking or rattling noises are present in the engine area, this should be diagnosed and repaired before replacing the sensor. (Otherwise you will only be wasting your money.)

Jun 11, 2011 | 1997 Dodge Caravan

2 Answers

My 2000 yukon knock sensor code came up. the shop said $ 700 to replace. the 5.3 motor runs great. Does this need replacing?


the engine has two knock sensors they are mounted under the intake manifold, $700 sounds a bit high , i think i would price around, as to the question do you have to replace them, NO, but they are there it aid in the ignition control if the engine spark knocks these sensors are there to sense this. and also if one of the sensors is always reading as if the engine is spark knocking then the on-board computer will keep trying to ****** the timing and this will effect you power, and fuel millage.

Mar 22, 2011 | 2000 GMC Yukon XL

2 Answers

I have on 01 xterra-service engine light on-codes P1126 & P0325. I think the battery is about to go,could it be realated to codes? Otherwise what do the codes mean? Appreciate any help


Your battery has nothing to do with these codes. Your vehicles computers have detected a malfunction or failure in the system. This triggers these codes and sets your check engine light. Below I have listed the code meanings and some repair solutions.

P1126 - Throttle Position (Narrow Range) Sensor Circuit Malfunction.

Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not provided to the ECM.

Possible Causes For P1126:
- Harness or connectors (Throttle control motor relay circuit is open)
- Throttle control motor relay


P0325 - Knock Sensor Circuit Malfunction

The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the Powertrain Control Module (PCM) or Electronic Control Module (ECM).

Possible Causes For P0325:
- Knock sensor circuit short to ground.
- Knock sensor circuit short to power.
- Knock sensor circuit open.
- Damaged knock sensor.
- Damaged PCM or ECM

Possible Solutions:
- Repair or resecure harness or connector
- Replace knock sensor Bank 1 (Bank 1 if applicable)
- Replace PCM or ECM

The P0325 DTC is a very common problem with Nissan vehicles. On most Nissan vehicles the knock sensor is located on top of the engine block.

knock_sensor_infiniti.gif

Jan 20, 2011 | 2001 Nissan Xterra

1 Answer

Service soon light stays on.. had it checked at auto zone and came up with po327 knock sensor condition. Is this gona be an expensive car repair?


no, 30 minutes labor--you can do it yourself. part is $30. You have 2 of them. 327 is for bank 1, which is the back bank by the firewall. see picture below (the picture is bank 2, but location is same on other side).

To replace the knock sensor:
  • Disconnect the knock sensor wiring connector.
  • Then, unscrew the sensor.
  • Remove the knock sensor.
  • Reverse the procedures to install the part.
  • fed2730.gif
      A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark ****** than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.

    Oct 12, 2010 | 1999 Pontiac Grand Am GT

    2 Answers

    How to repalce a knock sensor on my 2004 gmc yukon


    Hi welcom to fixya. A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark ****** than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.
    To replace the knock sensor:
    • Disconnect the knock sensor wiring connector.
    • Then, unscrew the sensor.
    • Remove the knock sensor.
    • Reverse the procedures to install the part.
    • 15 ft.lbs.torque
    • hope this helps.Thank You for using fixya..iluv2fish.. Ray..

    Jul 09, 2010 | 2004 GMC Yukon

    1 Answer

    Knock sensor replacement ....2003 kia rio....emissions ...obd II....failure...need to pass inspection...failure code P0325 (Knock sensor 1 circuit malfunction)....where vis the knock sensor located on a...


    Turn ignition off. Disconnect knock sensor 3
    -
    pin harness connector. Locate knock sensor, on cyli
    nder block.
    On Optima 2.7L engine, sensors are located on both
    sides of cylinder block. . Remove knock
    sensor from cylinder block. To install, reverse rem
    oval procedure.

    Mar 19, 2010 | 2003 Kia Rio

    Not finding what you are looking for?
    Cars & Trucks Logo

    Related Topics:

    50 people viewed this question

    Ask a Question

    Usually answered in minutes!

    Top Lexus Experts

    yadayada
    yadayada

    Level 3 Expert

    75817 Answers

    ROBERT GARCIA
    ROBERT GARCIA

    Level 3 Expert

    881 Answers

    Colin Stickland
    Colin Stickland

    Level 3 Expert

    22156 Answers

    Are you a Lexus Expert? Answer questions, earn points and help others

    Answer questions

    Manuals & User Guides

    Loading...