Common 1997 to 2005 Lexus GS300 Problems

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.

Shop 2nd Gen Lexus GS300 Parts

• Ball joints
• Mass Air Flow (MAF) Sensor
• Oxygen (O2) Sensors
• Variable Valve Timing (VVT) Solenoid
• Door Lock Actuator
• HVAC Servo Motor

Related Content

• 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]

2nd Generation Lexus GS300 Model Years

• 1997 Lexus GS300
• 1998 Lexus GS300
• 1999 Lexus GS300
• 2000 Lexus GS300
• 2001 Lexus GS300
• 2002 Lexus GS300
• 2003 Lexus GS300
• 2004 Lexus GS300