CARFIX

Mercedes-Benz S-Class 420 SEC (1985–1987)

The Mercedes-Benz S-Class (W126) of 1985-1987 embodies the golden standard of luxury and engineering prowess. Constructed with an unwavering commitment to quality rather than affordability, the S-Class has left an indelible mark on the automotive industry. Respected for its unmatched comfort and sophisticated design, many of these iconic cars still cruise the roads of New Zealand today. Are you contemplating whether this remarkable vehicle is the right investment for you? Let's explore what makes it special, along with essential maintenance tips that every owner should know.

Parts for the Mercedes-Benz S-Class 420 SEC

Known issues

Rust is a primary concern, especially around the jacking points, wheel arches, and fuel filler neck. Early fuel injection systems (KE-Jetronic) can be temperamental and difficult to diagnose. The vacuum-operated central locking system is also prone to leaks and failures. Air conditioning systems often need attention.

WOF tips

Rust, particularly around suspension mounting points and brake lines, is scrutinized during WOF inspections. Suspension components wear over time, leading to potential failures. Ensure all lights are functioning correctly, and that the brakes are in good condition. The handbrake mechanism can also become seized with age.

About the Mercedes-Benz S-Class 420 SEC

The early W126 models captured hearts with their robust construction and comfortable cruising capacity, offering everything from a smooth inline-6 to a powerful V8 engine. While generally reliable, some of these beauties might have experienced high mileage and deferred maintenance, making thorough inspections vital before purchase. Alongside that classic experience, potential buyers should know to check the interior for sun damage and wear. Pay special attention to the complex electrical components, like the often temperamental climate control system.

Rust is a prevalent concern, particularly in coastal areas, especially near jacking points, wheel arches, and the fuel filler neck. To maintain this vehicle's pristine condition, it’s crucial to consider service intervals for various parts. For instance, the cooling system typically requires inspection around 150,000 km, advising you to check the water pump, thermostat, and radiator hoses to ensure everything runs smoothly. [This naturally links to /shop/cooling] Additionally, early fuel injection systems (KE-Jetronic) may present diagnostic challenges, so staying proactive about maintenance can save you from future headaches. Don’t forget about the braking system, which is critical for safety; ensure your brake pads, rotors, and drums are in optimal condition. [Explore our /shop/braking category for quality parts] Lastly, regular air filter service will help maintain the engine efficiency and overall performance. [Check out our /shop/filtration for air and oil filter replacements] This unique blend of classic luxury demands attention but promises incredible rewards for devoted owners.

Questions owners ask

What are the common rust spots I should inspect on a 1985-1987 Mercedes-Benz S-Class (W126) in New Zealand?
Given New Zealand's coastal climate, rust is a significant concern. Pay close attention to the jacking points, wheel arches, and the fuel filler neck. These areas are particularly susceptible to corrosion on the 1985-1987 Mercedes-Benz S-Class (W126).
The air conditioning in my 1986 Mercedes-Benz S-Class isn't working well. What are the likely causes and how difficult is it to fix?
The air conditioning systems in the early W126 S-Class models are known to require attention. Common issues include leaks in the system, a failing compressor, or problems with the climate control unit itself. Diagnosis can be tricky, and repairs often require specialized tools and knowledge, so a workshop is recommended.
Where can I get brake pads for my 1985–1987 MERCEDES-BENZ S-CLASS in NZ?
CARFIX stocks 60 SKUs for the MERCEDES-BENZ S-CLASS 1985–1987, including brake pads. You can find suitable brake pads in our /shop/braking category.
What should I check on my 1987 Mercedes-Benz S-Class (W126) to ensure it passes its WOF in New Zealand?
During a WOF inspection, rust is a major concern, especially around suspension mounting points and brake lines. Also, ensure all lights are functioning correctly, the brakes are in good condition, and the handbrake mechanism isn't seized. Suspension components are also checked for wear.
My 1985 Mercedes-Benz S-Class has a rough idle. What could be causing this, and is it a difficult fix?
Rough idling in the 1985-1987 Mercedes-Benz S-Class (W126) can often be attributed to issues with the early KE-Jetronic fuel injection system. This system can be temperamental and difficult to diagnose without specialized equipment. Other potential causes include vacuum leaks or faulty sensors. A workshop with experience in classic Mercedes-Benz vehicles is recommended.
How often should I replace the air filter on my 1985-1987 Mercedes-Benz S-Class to maintain engine efficiency?
Regular air filter service is crucial for maintaining engine efficiency. While the exact interval depends on driving conditions, a good practice is to inspect the air filter every 10,000 km service and replace it if it's dirty. You can find replacement air filters in our /shop/filtration category.
What's the recommended service interval for my 1985-1987 Mercedes-Benz S-Class?
The recommended service interval for your 1985-1987 Mercedes-Benz S-Class is 10,000km. Regular servicing will help maintain its classic luxury experience.