Diagnose and Repair: 2nd Gen GS300 Issues
Lexus GS300 problems with the ball joints, mass airflow sensor, and door lock actuators are actually common. Like all models, the 2nd generation of the Lexus GS300, years 1997-2005, has its particular faults. Learn about these and more as this article covers the most common problems with the 2nd gen Lexus GS300.
1. Bad Ball Joints
Symptoms of Bad Ball Joints
- Squeaking from the wheel while driving
- In a worst case scenario, the ball joint separates and knocks the wheel and knuckle into the fender
Causes of Bad Ball Joints
Ball joints wear out over time and can loosen and separate if not replaced after signs of wear. This can happen on any car and can put you in a dangerous situation, but the ball joint wears out much more quickly in this case, making it one of the Lexus GS300 problems that should be fixed at the first sign of an issue.
How to Fix Ball Joint Problems on the 97-05 Lexus GS 300
Test the Ball Joint
- Raise and secure the car with a jack and jack stands. Grab the tire from the 12 and 6 o’clock positions. Press the tire in and out, feeling for looseness or play at the ball joint
Replace the Ball Joint
- Replace the ball joint. This option is safer than trying to re-grease one, which should wear out sooner than a new ball joint.
2. Dirty Mass Air Flow (MAF) Sensor
Symptoms of a Bad MAF Sensor
- Car loses power while driving down the road
- Transmission doesn’t shift right
- Drop in gas mileage
- Check engine light for codes P0171 and P0174
Causes of a Bad MAF Sensor
The mass air flow sensors on the 97-05 Lexus GS 300 don’t always go bad but they do get dirty. Particles and debris that get past the engine air filter may clog up the MAF sensor, affecting readings.
How to Fix a Dirty or Broken MAF Sensor
If you remove the MAF sensor, you’ll notice a blue dot, which is where the sensing agent is located. If the sensing agent is dirty or black, try cleaning the sensor with elements cleaner or mass air flow sensor cleaner. Do not use other auto parts cleaners like brake cleaner since those can damage the sensor. If cleaning the sensor does not change engine performance, replace the MAF sensor.
2. Defective Oxygen (O2) Sensors
Symptoms of Faulty O2 Sensors on the 97-05 Lexus GS 300
- Check engine light for a code indicating a bad heater circuit on an O2 sensor
Causes of Bad O2 Sensors
The O2 sensors have a heater circuit inside of them that is supposed to spark when the car is started so it can take readings. If the circuit fails, it will trigger a check engine light.
How to Fix Bad O2 Sensors
- You can test the condition of the O2 sensors by swapping them and seeing if the code reads for a different location
- Check the O2 sensor’s electrical connector and wiring, but usually it’s the O2 sensors that fail
- Inspect the O2 sensor wiring for splitting or fraying
- Inspect the electrical connector for corrosion or discoloration
4. Bad Variable Valve Timing (VVT) Solenoid
Symptoms of a Bad VVT Solenoid
- Check engine light for code P1349
- Lack of engine power
- Possible engine oil leak
Causes of a Bad VVT Solenoid
Sometimes the VVT solenoid fails, and other times it fails from other factors, such as lack of oil pressure from an oil leak.
How to Fix a Defective VVT Solenoid
The VVT solenoid is located on the top of the valve cover and underneath the engine cover. Check the GS300’s mechanical timing. If the timing is on, look for oil leaks around the VVT solenoid. If there are no signs of leaking, replace the VVT solenoid.
5. Faulty Door Lock Actuators
Symptoms of Broken Door Lock Actuators
- Door won’t lock or unlock after pressing the remote
Causes of Bad Door Lock Actuators
Sometimes the door doesn’t open because the electrical connection is faulty from a bad electrical connector or broken wires, but it’s usually because the door lock actuator is defective.
How to Fix a Faulty Door Lock Actuator
- Check the door lock actuator‘s electrical connector for corrosion or discoloration, and check the wiring for splitting or fraying
- If the connector and wiring are fine, replace the door lock actuator
6. Bad HVAC Servo Motor
Symptoms of a Faulty HVAC Servo Motor
- Airflow direction does not change after pressing the “mode” button
- Car fails to recirculate airflow after pressing the “recirculation” button
Causes of a Bad HVAC Servo Motor
If airflow is failing to blow from where it is commanded, the HVAC servo motor has failed
How to Fix the HVAC Servo Motor
Steps to remove the HVAC servo motor include
- Disconnecting the electrical connector
- Checking the terminals on the servo motor for discoloration
- Checking the wiring for breaking or tearing
Below you will find parts and related content for repairs and helpful tips when you experience one of these common Lexus GS300 problems.
- Ball joints
- Mass Air Flow (MAF) Sensor
- Oxygen (O2) Sensors
- Variable Valve Timing (VVT) Solenoid
- Door Lock Actuator
- HVAC Servo Motor
- Bad Ball Joint? [Expert Advice to Diagnose & Fix]
- MAP vs. MAF vs. IAT Sensors
- How to Test a MAF Sensor
- What Is an O2 Sensor?
- Are Your Car Door Locks Stuck?
- Car Door Won’t Shut or Open?
- Remote Key Won’t Unlock Car Door? [Expert Tips to Diagnose & Fix]