2004 Subaru Impreza
2004 Subaru Impreza
Overview
The 2004 Subaru Impreza, particularly in its WRX and STI variants, is renowned for its performance and rally-inspired capabilities. While generally considered a robust vehicle, certain model years and specific configurations can exhibit characteristic issues. This analysis focuses on common mechanical and electrical concerns reported by owners and technicians, excluding routine maintenance. Understanding these potential pitfalls can help owners budget for and address them proactively, ensuring the longevity and optimal performance of their Impreza.
Engine
2.0L Turbocharged EJ205 (WRX)
Head Gasket Failure
- Symptoms: Coolant loss, white smoke from exhaust, overheating, milky oil.
- Solution: Replacement of head gaskets, often with upgraded multi-layer steel gaskets.
- Cost: $1500 - $3000
Turbocharger Failure
- Symptoms: Loss of power, excessive smoke, whining noises, boost leaks.
- Solution: Rebuild or replacement of the turbocharger.
- Cost: $1000 - $2500
Piston Ring Wear
- Symptoms: Excessive oil consumption, blue smoke from exhaust, loss of compression.
- Solution: Engine rebuild with new piston rings.
- Cost: $2000 - $4000+
2.5L Turbocharged EJ255/EJ257 (STI)
Head Gasket Failure
- Symptoms: Coolant loss, white smoke from exhaust, overheating, milky oil.
- Solution: Replacement of head gaskets, often with upgraded multi-layer steel gaskets.
- Cost: $1500 - $3000
Piston Ring Land Failure (Pistons)
- Symptoms: Knocking noises, loss of power, excessive oil consumption, rough idle.
- Solution: Engine rebuild with forged pistons.
- Cost: $3000 - $6000+
Cracked Cylinder Sleeves
- Symptoms: Coolant/oil mixing, loss of compression, engine misfires.
- Solution: Engine replacement or sleeve repair.
- Cost: $4000 - $8000+
2.5L Naturally Aspirated EJ253 (Non-Turbo)
Head Gasket Failure
- Symptoms: Coolant loss, white smoke from exhaust, overheating, milky oil.
- Solution: Replacement of head gaskets.
- Cost: $1200 - $2500
Transmission
5-Speed Manual (Non-STI)
Clutch Wear
- Symptoms: Slipping clutch, difficulty shifting, grinding noises.
- Solution: Clutch kit replacement (clutch disc, pressure plate, release bearing).
- Cost: $600 - $1200
Synchronizer Issues
- Symptoms: Grinding when shifting into certain gears, difficulty engaging gears.
- Solution: Transmission rebuild or replacement of synchronizer rings.
- Cost: $1500 - $3000
6-Speed Manual (STI)
Gear Grinding (especially 2nd and 3rd)
- Symptoms: Grinding noise when shifting into specific gears.
- Solution: Transmission rebuild, often involving replacement of synchronizers and gears.
- Cost: $2000 - $4000
Clutch Wear
- Symptoms: Slipping clutch, difficulty shifting, grinding noises.
- Solution: Clutch kit replacement.
- Cost: $700 - $1300
4-Speed Automatic
No widespread issues reported.
- Symptoms: N/A
- Solution: N/A
- Cost: Varies
Suspension
Standard Chassis
Worn Ball Joints and Tie Rod Ends
- Symptoms: Clunking noises over bumps, vague steering, uneven tire wear.
- Solution: Replacement of worn suspension components.
- Cost: $400 - $800
Sagging Springs
- Symptoms: Reduced ride height, poor handling, uneven stance.
- Solution: Replacement of coil springs.
- Cost: $500 - $900
STI Suspension
No widespread issues reported.
- Symptoms: N/A
- Solution: N/A
- Cost: Varies
Electrical
General Electrical System
Faulty Window Regulators
- Symptoms: Power windows not operating, slow window movement.
- Solution: Replacement of window regulator motors or mechanisms.
- Cost: $200 - $400
Instrument Cluster Failures
- Symptoms: Intermittent gauge operation, dead pixels on displays, warning lights staying on.
- Solution: Repair or replacement of the instrument cluster.
- Cost: $500 - $1000
Exterior
Body and Paint
Rust Formation (especially wheel arches and sills)
- Symptoms: Visible rust bubbles, corrosion on lower body panels.
- Solution: Rust repair and repainting.
- Cost: $500 - $2000+
Headlight Condensation
- Symptoms: Moisture inside headlight assemblies.
- Solution: Sealing headlight assemblies or replacement.
- Cost: $100 - $400
Interior
Cabin Components
HVAC Blower Motor Failure
- Symptoms: No airflow from vents, or intermittent airflow.
- Solution: Replacement of the blower motor.
- Cost: $200 - $400
Door Lock Actuator Failure
- Symptoms: Power locks not working on one or more doors.
- Solution: Replacement of the door lock actuator.
- Cost: $150 - $300
Summary Verdict
The 2004 Subaru Impreza, while offering engaging driving dynamics, particularly in its turbocharged variants, presents several potential reliability concerns. The EJ-series engines, especially the turbocharged versions found in the WRX and STI, are prone to head gasket failures and, in higher-performance models, internal component damage like piston ring issues. Manual transmissions can experience synchronizer wear, while the STI’s 6-speed requires careful attention. Electrical gremlins like faulty window regulators and instrument clusters are not uncommon. Rust can also be a significant issue depending on climate. Despite these potential drawbacks, many issues are well-documented and repairable, making proactive maintenance and awareness key for owners of this enthusiast-focused vehicle.