The W124 series E-Class is an excellent example of what a proper Mercedes-Benz should be. As the direct successor to the W123, the W124 had very large shoes to fill within the product lineup. Built from 1985–1995, this versatile series from Sindelfingen was available as a sedan, station wagon, coupe and cabriolet, as well as a rare six-door version. 

History and background

The company faced a tall order to reinvent the midsize range following the much loved W123 (see The Star September-October 2020). Development of the W124 began in 1976; the final design was released at the end of 1984. The design was both revolutionary and a sensible step forward for Mercedes-Benz. A wide range of engines were available, as was newly-introduced 4Matic all-wheel-drive. In all, 2,058,777 units of the W124 were built. 

A fitting mantra for the W124 would be "form follows function." Design was overseen by Bruno Sacco, who ensured every aspect of the E-Class was reimagined. Many safety innovations of the W126 S-Class were incorporated into the new model. The exterior was engineered to satisfy multiple crash tests. The body was formed with integrated wind channels to optimize aerodynamics, yielding a very low coefficient of drag. The interior was designed with comfort and safety in mind, boasting a variety of features new to the E-Class, such as power seat adjusters, automatic climate control, and heated seats. 

A range of engines was available in the U.S. market, including a 3.0-liter inline six-cylinder gas engine, 3.0-liter 24-valve gas engine, six-cylinder turbo diesel engine, as well as a 4.2-liter and the mighty 5.0-liter V-8. Most W124s came with automatic transmissions and were rear-wheel drive, although you may still stumble across the occasional manual transmission vehicle. 

Starting in 1987, 4Matic AWD was available on the 2.6 and 3.0-liter gasoline and diesel sedans and station wagons. The C124 coupe was also launched that year. In 1988, ABS (Antilock Braking System) became standard; 1989 brought improvements in diesel engine emissions. The 500E was introduced in 1990, and the E320 cabriolet in 1991. The series saw a small update in equipment for the 1992 model year. The last two years of the W124 introduced a facelifted model with several notable updates. This included reworked styling, updated nomenclature with model designation before engine displacement (E320 vs 300E), as well as mild engine improvements. Station wagons featured a hydraulic self-leveling rear suspension system. This helped keep the car level under heavy loads. A Sportline sedan model was available with sport seats, a smaller steering wheel, seven-inch-width wheels, quick-ratio steering, tuned suspension with stiffer springs, struts, anti-roll bars, and a lower ride height. 

The W124 is considered to be one of the most durable Mercedes-Benzes ever built – just like its W123 predecessor. If the vehicle was taken care of, it will return the favor and take care of you. These bodies are less prone to rusting that earlier models due to advances in design, material use, and manufacturing. 

Known Issues

• Engines are all very reliable, although 1993-1995 models suffer from faulty bio-degradable wiring harnesses and throttle bodies. Six-cylinder models may need new head gaskets. You may even come across a diesel engine converted to run on used cooking oil; resist the appealing smell of French fry exhaust and walk away. Obtaining appropriate fuel in regular quantities can be a challenge. 
• Vacuum-operated climate control in the W124 is complex and expensive to repair. Coupes and cabriolets had self-presenting seatbelt arms; the gears in the motors often break, making them inoperable. Cabriolets suffer leaking soft-top hydraulic cylinders. 

The wolf in sheep’s clothing – 500E / E500 

• Regarded as the most desirable W124, the 500E/E500 was designed in close collaboration with Porsche. Engineers at Porsche were tasked to rework the W124 chassis to accommodate the massive 5.0-liter M119 V8. The suspension and braking systems were also upgraded. These changes made the car too wide to be produced on the W124 assembly line in Sindelfingen; hence Porsche was commissioned to build the 500E/E500. 
• The manufacturing process was quite elaborate, with an 18-day production schedule. Mercedes-Benz would deliver the parts to Porsche. The chassis would be hand-assembled and sent back to Mercedes-Benz to be painted. Once painted, vehicles once again returned to Porsche to fit the engine and other components. Vehicles were returned for final inspection and delivery at the Mercedes-Benz Sindelfingen plant. An AMG variant dubbed the E60 AMG was built in extremely limited numbers. 

Safety equipment

•  The W124 was created with passenger safety in mind. Crumple zones were integrated into the streamlined body. The chassis was engineered to withstand front and rear offset impacts even before government safety standards existed. In fact, the crash testing conducted by Mercedes-Benz was later used in the Euro-NCAP safety test development. 
• Front and rear windshields were designed to stay in place in the event of a collision. Doors were built to overlap other panels, allowing any door to always be opened, helping in emergency rescues. Coupes and cabriolets also have reinforced side panels due to the pillarless window design. The interior offers just as many innovations. All vehicles destined for the United States were fitted with a driver's airbag, and later a passenger airbag as well. Seatbelts are height adjustable and offer pre-tensioners in the event of an abrupt maneuver. Interior panels were soft and impact absorbing. The cabriolet offers two retractable rear headrests which double as a rollover bar in the event of a rollover. Front and rear fog lamps are equipped as standard. Later cars all featured ABS (Antilock Braking System), ASR (Anti-Slip Regulation), and SRS Airbags (Supplemental Restraint System). 

Reasons to buy 

• There is a W124 for everyone – four body styles were built, along with many gasoline and diesel engine options. 
• Many aspects of a W124 are serviceable by a mechanically inclined owner. 
• Multiple safety systems help create competent road handling. 
• Sufficient power output from diesel and gasoline engines. 
• Many interior options, including 10-way power heated seats, sunroofs, rear sunshades, automatic air conditioning, seatbelt extenders, and power windows all around. 
• Interior components and materials are all very durable.
• Seating position and visibility is excellent for all variants. 
• A well-kept W124 can be purchased for a reasonable price. 
• The 400E/E420 offers great performance for a fraction of the cost of a 500E/E500. 
• Manual transmission available on 1986-1987 260E and 300Es. 
• Station wagon models offer many conveniences including the third-row rear-facing jump seat. 
• Cabriolet tops are well insulated, with a glass rear window. 

Reasons not to buy 

1993-1995 cars had expensive to replace biodegradable wiring harnesses. Also, cars may need a throttle body rebuild. 

• All six-cylinder models are prone to head gasket failure. 
• Diesels may have issues with the cylinder head. 
• V-8 engines are shoehorned into these cars; there is not a lot of room to work under the hood. 
• Cabriolet soft top hydraulics fail and require rebuilding. 
• Vacuum-operated air conditioning systems are problematic. 
• Owners neglect to replace the many suspension bushings. 
• Seatbelt presenters on coupe and cabriolet are prone to failure. 
• Plastic interior parts become fragile and prone to cracking. 
• Self-levelling rear suspension on wagons and 500E are often neglected. A bouncy ride means accumulators need replacement. 
• Complicated windshield wiper gears tend to fail. 
• Reverse gear can fail.

Checkpoints 

• Check the body for rust. Common rust points include jack points, sunroof trays, battery trays, trunk near spare tire, front fenders where bumper meets metal. 
• Check climate control system and inspect that air is being delivered properly in each respective mode. 
• Check six-cylinder cars for excessive oil consumption and leaks from the head gasket. The water pump, belt tensioner, and radiator have a life span of 80,000 to 100,000 miles. 
• Inspect the car’s wiring harness; 1993-1995 biodegradable harnesses may have cracked insulation. 
• Inspect suspension components for creaks and noises. 
• Bad self-leveling suspension accumulators will generally cause a harsh bouncy ride over bumps, requiring replacement. 
• Inspect reverse gear for engagement or rough shifting. 
• Diesel vacuum pumps are prone to failure. 
• The 2.5-liter diesel timing chain stretches prematurely. 
• Early model rear subframe is susceptible to cracking. 
• Inspect the sunroof for smooth operation and leakage. 
• Inspect any loose interior panels. It is not uncommon for a headliner to begin to sag. 
• Rear window regulators are prone to failure. 

Finally

With advanced engineering, reliability and safety, plus many models and engines from which to choose, the W124 offers today’s enthusiast a remarkable value opportunity to acquire a classic Mercedes-Benz with modern car useability.