The Mercedes Benz S-Class W220, produced from 1998 to 2005, represents a generation of flagship luxury sedans known for their groundbreaking technology, refined comfort, and powerful performance. However, like any complex machine, particularly one with some years and miles, the Mercedes S-Class W220 has its quirks. This guide aims to equip you with the knowledge to navigate common issues and keep your S-Class running smoothly for years to come.

Mercedes Benz S-Class W220 Brief Background

This Mercedes S-Class was an automobile technology game-changer that introduced the following:

Airmatic Suspension: This electronically controlled air suspension was revolutionary, giving you a cloud-like ride and handling that defied the car’s size.
COMAND System: The precursor to today’s infotainment systems, this was cutting-edge for its time, integrating navigation, audio, and vehicle functions.
Safety First: Packed with ESP, Brake Assist, and Distronic (early adaptive cruise control), this car was ahead of its time in safety tech.
Engine Choices: From the silky smooth V8s in the S430 and S500 to the monstrous V12 in the S600.

The W220 Common Issues and How to Fix them

Now, let’s get our hands dirty. Here’s the lowdown on the problems you might encounter, categorized by system, and drawing on years of experience and countless forum threads:

Engine:

M112 and M113 V8 Engines (S430, S500):
- Oil Leaks: Valve cover gaskets, oil filter housing gaskets, and the front crankshaft seal are the usual suspects. Solution: Replace the gaskets. Don’t cheap out on parts – use genuine Mercedes or high-quality aftermarket.
- Secondary Air Injection (AIR) System: The pump can fail, or the valves can get clogged. Solution: If it’s the pump, replace it. For clogged valves, try cleaning them, but replacement is often necessary.
- Catalytic Converters: They can clog up with age. Solution: Replace them. Aftermarket cats can be more affordable, but make sure they meet emissions standards.
- Lesser-known quirk: Early M112s (pre-2003) can have timing chain guide wear. Solution: If you hear rattling on startup, get it checked ASAP. Replacing the guides is a big job, but it’s better than a destroyed engine.
M275 V12 Engine (S600):
- Turbocharger Issues: Oil leaks and wastegate actuator failures are common. Solution: For leaks, replace the seals or, in worse cases, the turbos. For actuator problems, you can sometimes rebuild them, but replacement is often more reliable.
- Ignition Coil Packs: These tend to fail. Solution: Replace them. It’s often best to do them all at once to avoid future issues.
- Lesser-known quirk: The intercooler pump can fail. Solution: Replace the pump. Ignoring this can lead to overheating and engine damage.

Transmission:

722.6 5-Speed Automatic:
- Conductor Plate: This electronic component controls shifting and can malfunction. Solution: Replace the conductor plate. Make sure to get the updated version, which is more reliable.
- Torque Converter: The lockup clutch can wear out, causing shuddering. Solution: Replace the torque converter. This is a pricey repair, but it’s the only fix.
- Lesser-known quirk: The pilot bushing in the bellhousing can wear out. Solution: Replace the bushing. It’s a small part, but it can make a big difference in shifting smoothness.

Electrical:

COMMAND System: Screen pixels can fade, and the unit can have software glitches. Solution: For pixel issues, you might be able to find a replacement screen. For software problems, a reset or update might help, but sometimes the whole unit needs replacing.
Door Lock Actuators: They can fail, leaving you locked out. Solution: Replace the actuator. It’s a common problem, so parts are readily available.
Window Regulators: These can break, making the windows stick. Solution: Replace the regulator. It’s a fairly common repair.
Battery Drain: Various modules can draw power even when the car is off. Solution: Have the battery and charging system tested. Use a multimeter to check for parasitic draw and identify the culprit module.
Lesser-known quirk: The fiber optic cables connecting the electronics are fragile. Solution: Handle them with care. If one breaks, you’ll need to replace it, which can be tricky.

Suspension:

Airmatic:
- Air Struts: These can leak or fail, causing the car to sag. Solution: Replace the struts. Arnott Industries makes good aftermarket options.
- Compressor: It can fail from age or overuse. Solution: Replace the compressor. Again, Arnott is a good source for replacements.
- Valve Block: This controls air distribution and can leak or malfunction. Solution: Replace the valve block. This can be a tricky job, so you might want to leave it to a pro.
- Lesser-known quirk: The Airmatic relay can fail. Solution: Replace the relay. It’s a cheap and easy fix.

Body:

Rust: W220s can rust, especially around the wheel arches, jack points, and underbody. Solution: Catch it early and have it repaired by a body shop. Regular washing and waxing can help prevent rust.
Sunroof Drains: Clogged drains can cause water leaks. Solution: Clean the drains regularly. You can use a thin wire or compressed air to clear them.
Lesser-known quirk: The trunk lid wiring harness can fray. Solution: Repair or replace the harness. This can cause problems with the trunk release and taillights.

Benz W220 Maintenance Procedures

Keeping your W220 happy means staying on top of maintenance:

Fluids: Engine oil, transmission fluid, coolant, brake fluid, and differential fluid need regular changes. Stick to the recommended intervals in your owner’s manual.
Airmatic: Inspect for leaks, check the compressor, and consider proactively replacing aging parts like the relay and valve block.
Electrical: Test the battery and charging system regularly. Clean the battery terminals and check for corrosion.
Body: Wash and wax regularly. Check and clean those sunroof drains!

Mileage-Based Maintenance:

30,000 miles: Replace engine air filter, cabin air filter.
60,000 miles: Replace spark plugs, transmission fluid and filter (if not done previously), brake fluid.
90,000 miles: Replace coolant, differential fluid, serpentine belt.
120,000 miles: Inspect and service Airmatic components (struts, compressor, valve block).

This is just a general guideline. Always consult your owner’s manual for specific recommendations.

S-Class DIY Tips

For the DIYers out there, here are some jobs you can tackle:

Oil Changes: It’s pretty straightforward with the right tools and a good filter.
Air Filter & Cabin Air Filter Replacement: Easy peasy.
Spark Plug Replacement: Requires some tools and know-how, but it’s doable.
Brake Pad Replacement: Another relatively simple job with the right tools.

Important Note: While some maintenance is DIY-friendly, leave the complex stuff to the pros. Don’t be afraid to seek out a good independent Mercedes specialist.

Resources:

Forums: Benzworld, MBWorld, and PeachParts are your best friends.
YouTube: Tons of videos showing how to do various repairs.
Independent Shops: Find a good one specializing in Mercedes.

With a bit of knowledge and preventative maintenance, your W220 S-Class will provide years of luxurious driving. Enjoy the ride!