Buyers Guide – 1977-1985 W123

The elegant and understated W123 remains arguably the best Mercedes-Benz ever built.

Article by Pierre Hedary

Technical data by Richard Simonds

Images courtesy Daimler Archives.

When we wrote the first W123 Buyers Guide seven years ago, fuel was $4 per gallon, the economy was in crisis and there was an alternative-fuels craze taking the vintage diesel-car community by storm. One result was that W123s – especially the diesels – started becoming desirable because of their mechanical fortitude, ease of repair and reliability. Now they’re even more popular.

Today, even a cheap new car can cost more than $25,000 – and the control modules that govern the engines have a limited life span and then burn out like Christmas tree lights. A new set of values drives the kind of person who has fallen for the W123, and that person is tired of dealing with the electronic and mechanically planned obsolescence of the modern-family car.

Not to say that the W123 isn’t collectible – a solid, clean W123 will garner its fair share of attention everywhere it goes. An example  of the breed painted in the Stuttgart company’s famous earth-tone colors has the aesthetic draw of a young Brigitte Bardot – innocent looking and sweet – a little car that had the sole job of making its drivers smile. And in a world of $10-million vintage Ferraris, this certainly counts for a lot.

Background

The W123 was built from 1977 to 1985 for the U.S. market and can unofficially be divided into three different eras.
The first era of W123s, including the 240D, 300D, 280E and the all-but-forgotten 230 in the U.S. market, lasted until August 1979. A plethora of additional models was available in other markets. These four-door sedans had textured seat covers, textured dashboards, clear fog lights, flat steering-wheel pads and diesel engines with large, serial glow plugs. They were generally less powerful than the later cars, and they also used automatic transmissions with a mechanical linkage to control shifting. The color palette was very diverse, although the durability of their interiors was lacking.

For model year 1978, a coupe was added; four different engines were available. The 280CE was introduced, as well as the 300CD, which was unique to the U.S. market. In 1979, a station wagon with several engine options was added to the lineup, but in the United States we only received the 300TD.

The second era began in September 1979. The biggest change involved switching to parallel glow plugs on diesels and incorporating a vacuum modulator control to smooth shifting on diesels with automatic transmissions. The M110 engine was left unchanged while the 230, with relative fuel-economy issues, was withdrawn from the U.S. market.

The easiest way to identify the second-version cars is by their dished steering wheel, smooth dashboard and updated seats. In August 1980, the station wagon received the turbodiesel engine that was used in the 300SD. By May 1981, the 300CD was also equipped with this engine. This is, to my mind, the most brilliant thing Mercedes has ever done. By 1982, the entire lineup was powered by diesel engines; the only non-turbo-charged option was the excellent 240D. Subsequently, the 300D turbo became the most popular Mercedes-Benz sold in the United States. Also in 1981, Mercedes updated the climate-control unit on the 300D and 280E for more reliability.

In 1983, Mercedes-Benz updated the model range once more. While subtle alterations were made to the interior, illuminated sun visors were the most obvious change. 1983 also proved to be the last year for the venerable U.S.-market 240D, which was replaced by the less-durable 190D. Up until 1985, Mercedes continued to supply the 240D in Europe, where it sold well until the end of production.

The venerable 300D and its variants were updated one more time in 1985. The two biggest improvements included a boost in horsepower, a 2.88 rear-axle ratio and a more effective shift-control device, known as a pressure converter. Devoted fans of the car believe that Mercedes could have sold the 123 for at least another five years, but all good things must come to an end.

With production totaling 2.7 million vehicles and available as a sedan, coupe or station wagon, it’s relatively easy to find the W123 that’s right for you. 300CD turbodiesel sedan, coupe and station wagon built for U.S. market.

Renowned for dependability and safety, many W123s became taxis.

Reasons to buy a W123

Amazing robustness and reliability, and easy to maintain. A huge online DIY community is happy to share information

No control modules or engine-management systems to fail; diesels can even run without a working battery or alternator
Excellent suspension and handling, with brakes to match.

Excellent design characteristics with attractive proportions, and amazing all-around visibility adds to the car’s desirability

Unlike other older cars, new spare parts are readily available from both Mercedes and OEM suppliers at reasonable prices

With continuing maintenance, the basic structure of the car could last forever. Components are long-lived and rebuildable
Environmentally friendly – buy a W123 and that’s one less new car on the road, and one less old car for the planet to reabsorb

Reasons not to buy a W123

Don’t buy one for your teenage son or daughter just because it seems safe. There are safer and equally practical Mercedes-Benz cars available, such as the W202 C-Class or W210 E-Class

Fuel economy: Once offering relatively good fuel efficiency, today the W123s are only average

Ability to burn alternative-fuels is a feature, not an advantage; avoid W123s converted to run on recycled vegetable oil
Acceleration and high speed are not their strong suits

W123s require regular attention to stay “right.” If you need a cheap car that you can drive and forget, buy a used Hyundai
Aesthetic appeal: They do look cool. Then reality sets in, and owners find that even cool cars need maintenance and repairs

Check Points

While the W123 range is renowned as a very hardy and repairable automobile, many of the models can be overpriced and tend to have a number of common issues.

Look for rust in the sunroof tray, floor pans, battery-tray area and doors. Station wagons also rust near their back windows. Other areas do rust, but these are the most difficult to fix.

Oil consumption should be examined closely. A good example won’t use more than a quart between services; a quart every 800 miles is not great but still acceptable.

Dashboards crack and replacements are not easily found.

Watch out for vacuum issues and be prepared to fix a few of them, especially in the vacuum door locks and climate control

Watch out for diesels that were used as waste-vegetable oil burners; a new injection pump might be in your future.

Front suspensions need rebuilding at about 150,000 miles. Factor in about $1,500-$2,000, using high-quality parts.

Test a/c compressor, climate control thoroughly; repairs can be done but are costly; factor that into your purchase price.

Rear CV axles occasionally need replacement. Correct GKN axles are expensive, so factor this into the purchase price.

Seats eventually decompose in the 1977-82 W123 models. Repairs are straightforward, but new excelsior pads and seat covers cost more than $2,000.

Rear power-window regulators can wear out and will make a clattering noise when the window reaches maximum height. Window wiring can also break where the doors open and close.

Plastic radiators, windshield gaskets, engine mounts, drive-shaft flex discs and the like should be checked carefully.
 

The bottom line

To many of us who own W123s, these aren’t just old cars; they are the best automobiles ever built. There are examples for every budget: Plenty of low-mileage cars exist that anyone would be proud to show, and there are many great, usable examples available for daily use – this writer has driven examples out of wrecking yards just by putting in a hot battery and air in the tires.

But every old car has problems. In the case of the W123s, which are nearly impervious to mileage, it seems that Mercedes has gradually trimmed the supply of unique interior and exterior trim items available. While many used parts do exist, more perishable items – especially in specific colors, such as an uncracked blue dashboard – are nearly impossible to find. Consider this when purchasing and look for a car that has visible components and details intact.

A car with a few issues may still be a good buy; just buy at a price where a few thousand dollars of repairs won’t make you unhappy. Negotiate aggressively, particularly on the station wagons. Question any claim of “no needs.” Bottom line: Next to the famous 300SL, the W123s might be the most iconic cars Mercedes-Benz ever built. If you haven’t owned one, you’re missing out.

W123 Sedan

Data and Specifications

MODEL    YEARS    CHASSIS    ENGINE    HP    TORQUE    PRODUCED

200      1976-1980     123.020    115.938    105    116.5    158,772

200      1980-1985     123.220    102.920    122    125.2    217,315

230      1975-1980     123.023    115.954      86    136.7    196,185

230E    1979-1985     123.223    102.980    152    151.2    245,558

250      1975-1985     123.026    123.920    144-156     144.7    122,864

280      1975-1981     123.030    110.923    174      164.2    33,206

280E    1975-1985     123.033    110.984    137-142    142-172    126,375

200D    1975-1985     123.120    615.940    61-67     83.2    378,138

220D    1975-1979     123.126    615.941    67         92.6    56,736

240D    1975-1985     123.123    616.912    62-67    97    454,780

300D    1975-1985     123.130    617.912    77-83    115-120    331,999

300D Turbo     1981-1985     123.133    617.952    118-123    170-184    75,261

C123 Coupe

MODEL    YEARS    CHASSIS    ENGINE    HP    TORQUE    PRODUCED

230C      1976-1980     123.043    115.954    122    136.7    18,675

230CE    1980-1985     123.243    102.980    152    151.2    29,858

280C       1976-1980     123.050    110.923    174    164.2    3,704

280CE    1976-1985     123.053    110.984    137-142    142-172    32,138

300CD    1977-1981     123.150    617.912    77-83    115-120    7,502

300CD Turbo    1981-1985     123.153    617.952    118-123    170-184    8,007

S123 Station Wagon

MODEL    YEARS    CHASSIS    ENGINE    HP   TORQUE    PRODUCED

200T      1980-1986     123.280    109.920    105    116.5    18,860

230T      1978-1980     123.083    115.954    86    136.7    6,884

230TE    1979-1986     123.283    102.980    152    151.2    42,284

250T      1977-1982     123.086    123.920    144-156    144.7    7,704

280TE    1977-1986     123.093    110.984    137-142    142-172    19,789

240TD    1978-1986     123.183    616.912    73-80    101.3    38.903

300TD    1977-1986     123.190    617.912    77-88    115-120    36,874

300TD Turbo    1979-1986     123.193    617.952    118-123    170-184    28,219

W123 Model Chronology

1975     September    European market 200, 230, 250 sedans released

1976     September    240D, 230, 280E, 300D replace W115 chassis in U.S. market

1977     September    U.S.-market 300CD coupe and 280CE coupe arrive

1978     August    U.S.-market 230 discontinued

1978     September    U.S.-market 300TD station wagon arrives

1979     April    R04 a/c compressor replaces York compressor

1979     August    Electronic glow plugs system released; diesel-model horsepower increased

1979     September    Modulator shift control replaces mechanical linkage on automatic transmissions

1980     September    300TD turbodiesel wagon released; 722.3 automatic transmission released; third-generation Automatic Climate Control

1981    May    300CD gets turbodiesel engine

1981     September    300D gets turbodiesel engine

1982     September    All model interiors, seats and carpeting upgraded

1983    September    240D discontinued

1984     August    300D & variants get 2.88:1 differential; vacuum system and turbocharger upgraded; vacuum controls refined; 722.3 automatic transmissions get new torque converter; California cars get trap oxidizer; 722.4 automatic transmission

1985     September    U.S.-market 123 chassis production ends

1986    January    European-market 123 chassis production end

The Mercedes-Benz W123 range was ahead of virtually every other manufacturer in terms of safety, serviceability, ergonomics, classic styling, long-term reliability and build quality. The 280E pictured here was a popular upper-range model, powered by a responsive gasoline engine rated at 137-142 horsepower.