🏷️ Basic Information

Make:

Kia

Model:

Optima

Year:

2004

Engine:

2.4L (146 cu in) DOHC I4

Generation:

Second Generation (MS/MG)

Chassis Code:

MS

👋 Introduction

Market Position:

The 2004 Kia Optima was positioned as a mid-size sedan offering a balance of value, features, and European-inspired styling, aiming to compete with established Japanese and American marques in a competitive segment.

Competitive Analysis:

Key competitors in 2004 included the Toyota Camry, Honda Accord, Nissan Altima, Ford Mondeo (in Europe), and Chevrolet Malibu. The Optima aimed to differentiate through its distinctive styling and competitive pricing.

Key Features:

The second-generation Optima (MS) featured a more refined exterior design, improved interior quality, and a focus on safety. It offered a choice of engines, including the 2.4L Theta I4 and a 2.7L V6 (though this manual focuses on the 2.4L).

📋 Manual Details

Coverage Areas:

Engine, Transmission (Automatic & Manual), Drivetrain, Suspension, Steering, Brakes, Electrical System, Climate Control, Body & Chassis, Maintenance, Troubleshooting, Diagnostics, Wiring Diagrams.

Page Count:

Estimated 1500-2000 pages (typical for a comprehensive service manual)

Manual Type:

Service and Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Systems Covered:

Engine Mechanical, Engine Control System (ECM), Fuel System, Ignition System, Emission Control System, Cooling System, Lubrication System, Intake System, Exhaust System, Automatic Transmission (AT), Manual Transmission (MT), Clutch, Drive Shafts, Axles, Differential, Suspension (Front & Rear), Steering System, Power Steering, Brakes (ABS, EBD), Parking Brake, Wheels & Tires, Electrical System (Wiring Diagrams, Fuses, Relays), Lighting System, Instrument Cluster, Audio System, HVAC System, Air Conditioning, Power Accessories (Windows, Locks, Seats), SRS Airbag System, Body Exterior, Body Interior, Frame and Bumpers.

Procedures Included:

Routine maintenance, Scheduled maintenance, Engine tune-up, Oil change, Filter replacement, Spark plug replacement, Timing belt/chain inspection and replacement, Cooling system flush and refill, Brake fluid replacement, Power steering fluid replacement, Transmission fluid change, Differential fluid change, Clutch adjustment, Brake pad and rotor replacement, Suspension component replacement, Steering component replacement, Wheel alignment, Electrical troubleshooting, Sensor testing, Actuator testing, ECM diagnostics, DTC (Diagnostic Trouble Code) interpretation and clearing, Component removal and installation, Reassembly, Torque specifications, Lubrication points, Wiring harness repair, Body panel repair, Interior trim removal and installation.

Technical Depth:

Comprehensive. Covers detailed diagnostic procedures, component-level repair, overhaul instructions, specifications for all major systems, and troubleshooting guidance for a wide range of common and uncommon issues.

📊 Manual Specifications

File Format:

Portable Document Format (PDF)

Print Quality:

High-resolution scans with clear, legible text and sharp diagrams. Optimized for digital viewing and printing.

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Displacement:

2.4 Liters (2351 cc)

Engine Type:

Inline 4-cylinder (I4)

Engine Code:

G4BP (Theta)

Valvetrain:

DOHC (Dual Overhead Camshafts), 16 Valves

Bore X Stroke:

86.5 mm x 101.0 mm

Compression Ratio:

9.5:1

Horsepower Net:

138 hp @ 5500 rpm (approximate, may vary slightly by market)

Torque Net:

147 lb-ft @ 4000 rpm (approximate, may vary slightly by market)

Fuel Delivery:

Electronic Fuel Injection (MPI - Multi-Point Injection)

Fuel Type:

Unleaded Gasoline (87 Octane recommended)

Fuel Tank Capacity:

15.5 gallons (approx.)

🔧 Transmission

Transmission Type Standard:

5-Speed Manual Transmission

Transmission Type Optional:

4-Speed Automatic Transmission (4-Speed SP with Electronically Controlled Overdrive)

Transmission Fluid Type:

ATF SP-III (for automatic transmission)

📐 Dimensions

Length:

186.1 inches (4727 mm)

Width:

70.1 inches (1781 mm)

Height:

57.3 inches (1455 mm)

Wheelbase:

106.3 inches (2700 mm)

Curb Weight:

3230-3380 lbs (approx., depending on transmission and features)

Gross Vehicle Weight Rating:

4500-4700 lbs (approx.)

Trunk Volume:

14.1 cubic feet (approx.)

🛡️ Safety Features

NHTSA Front Impact Driver:

Good

NHTSA Front Impact Passenger:

Good

IIHS Front Offset Driver:

Acceptable (for related model)

Active Safety Features:

Anti-lock Braking System (ABS), Electronic Brake-force Distribution (EBD), Traction Control System (TCS) (optional on some trims)

Passive Safety Features:

Front dual-stage airbags, Front side-impact airbags, Pretensioner seatbelts, Crumple zones, Side-impact door beams, LATCH child seat anchors.

💡 Technology Features

Infotainment System:

Basic AM/FM/CD stereo system with optional premium audio. Cassette player may be present on early models. Auxiliary input and Bluetooth connectivity are generally not standard features on this model year.

Driver Assistance Features:

Limited. Primarily relies on ABS and EBD for braking assistance. Cruise control is typically standard on most trims.

Connectivity Features:

Basic. May include power windows, power locks, and remote keyless entry. Trip computer and external temperature display available on higher trims.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles or 6 months, or 7,500 miles or 12 months with synthetic oil (refer to owner's manual for specific recommendation).

Air Filter Replacement Interval:

Every 15,000 miles or 12 months.

Cabin Air Filter Replacement Interval:

Every 15,000 miles or 12 months.

Spark Plug Replacement Interval:

Every 60,000 miles (NGK Platinum or Iridium plugs recommended).

Timing Belt Replacement Interval:

75,000 miles or 5 years (Critical maintenance item for the 2.4L Theta engine to prevent catastrophic failure).

Engine Oil Type:

API SJ or higher, SAE 5W-30 (Synthetic blend or full synthetic recommended)

Engine Oil Capacity:

4.0 US quarts (3.8 liters) with filter change.

Coolant Type:

Ethylene Glycol based coolant, Kia Super Long Life Coolant (PS anticongelante G-11 or equivalent blue/green coolant)

Coolant Capacity:

7.4 US quarts (7.0 liters)

Brake Fluid Type:

DOT 3

Power Steering Fluid Type:

ATF SP-III or equivalent power steering fluid.

Known Issues:

Potential for oil leaks from valve cover gasket and oil pan gasket. Engine mounts can degrade over time. ABS sensor failures leading to ABS warning light illumination. Climate control blower motor resistor failure. Some reports of premature wear in certain suspension components like ball joints and control arm bushings. Timing belt failure can cause significant engine damage if not replaced at recommended intervals.

📚 Vehicle History

Brand Heritage:

Kia Motors, a South Korean automotive manufacturer, has a history dating back to 1944. Initially producing motorcycle parts, Kia entered the automobile market in the 1970s and has grown significantly, focusing on value, reliability, and increasingly, distinctive design.

Model Evolution:

The Optima (known as the Magentis in some markets) debuted in 2000 as Kia's mid-size sedan offering, replacing the Kia Clarus. The 2004 model represents the second generation (MS/MG), which received significant styling and engineering updates compared to the first generation. This generation was also notable for its platform sharing with the Hyundai Sonata.

Production Years:

2000-2006 (First Generation), 2005-2010 (Second Generation - though 2004 model belongs to the end of the first generation's market presence, this manual likely covers the full first generation and potentially early second gen overlap in production timing).

Manufacturing Locations:

Primarily South Korea (Hwaseong Plant), with some assembly in other international locations.

🏆 Awards & Recognition

Recognitions:

While not a segment leader in awards, the 2004 Optima was recognized for its value proposition and styling in various consumer reviews and automotive publications of its time.

Ratings:

Often received mid-pack ratings in its class for driving dynamics and refinement, but typically scored well for price and features.

Certifications:

Compliant with Federal Motor Vehicle Safety Standards (FMVSS) in the United States.