2020 Subaru Wrx Camshaft Bearings

The valvetrain system in your 2020 Subaru Wrx is responsible for precisely controlling the opening and closing of engine valves. This camshaft bearings repair guide covers the complete diagnosis and repair procedure for this critical component.

Understanding the AVCS, AVLS System

Your 2020 Wrx is equipped with AVCS, AVLS technology, which optimizes valve timing for improved power, fuel efficiency, and emissions. The system uses hydraulic phasers, solenoid valves, and electronic controls to adjust valve events in real-time.

Common Symptoms of Camshaft Bearings

• Ticking or tapping noise from the valve cover area
• Rough idle or engine stumbling
• Decreased fuel economy
• Check engine light illumination
• Reduced power under acceleration
• Oil consumption between changes

Diagnosis Procedure

Step 1: Visual Inspection

Begin with a thorough visual inspection of the valve cover area. Check for:

• Oil leaks around the timing cover
• Cracked or brittle vacuum lines
• Loose or corroded electrical connectors
• Signs of oil starvation or contamination

Step 2: Mechanical Diagnosis

Perform compression and leak-down tests to verify valve train integrity. Listen carefully with a stethoscope probe along the valve cover rail to isolate the source of any noise.

Step 3: Electrical Testing

For VVT systems, use a multimeter to test:

• VVT solenoid resistance (typically 6-12 ohms)
• Oil control valve functionality
• Wiring harness integrity
• ECM communication codes

Repair Procedure

Tools Required

• Complete metric socket set
• Torque wrench (ft-lb and N·m)
• Timing chain holding tool
• Cam phaser lockout tools
• Press kit for bearing replacement
• RTV silicone sealant
• New gaskets and seals

Disassembly

1. Disconnect the negative battery terminal
2. Remove the valve cover and any intake components
3. Drain coolant and remove timing cover
4. Mark timing chain orientation with paint or markers
5. Remove timing chain tensioner and guides
6. Document bolt locations and torque sequences

Inspection

Inspect all components for wear:

• Timing chain stretch (max 3% elongation)
• Phaser vanes for scoring or wear
• Solenoid screens for blockage
• Oil passages for restrictions
• Chain guides for cracks or softening

Assembly

Follow exact torque specifications:

Timing Chain Installation

1. Install camshaft phasers in the correct orientation
2. Align timing marks precisely
3. Route chain without tension on the tensioner
4. Install tensioner and release plunger
5. Rotate engine 2 full revolutions to verify timing
6. Check for proper phaser operation

Post-Repair Verification

Start the engine and monitor:

• Oil pressure at idle (minimum 25 PSI)
• VVT operation via live data
• Check for leaks around all gaskets
• Verify proper idle quality
• Test drive under varying loads

Estimated Costs

• DIY parts: $150-400
• Professional repair: $800-2000
• Dealer service: $1200-3000

Prevention Tips

• Use manufacturer-spec oil and filters
• Change oil at recommended intervals
• Avoid extended idling with low oil
• Address any oil pressure warnings immediately
• Follow the 2020 maintenance schedule

Performing this camshaft bearings repair will restore your engine's performance and prevent potential catastrophic engine damage. Always double-check timing alignment before buttoning up the engine.