Junkyard Gem: 1982 Buick Riviera Diesel Coupe

After appending the Riviera name to various cars during the 1950s, Buick finally made the Riviera a model in its own right for the 1963 model year. Seven more generations of Buick’s rakish personal luxury coupe followed over the next 36 years, but only one ever had an oil-burning engine available from the factory. Today’s Junkyard Gem is one of those cars, a vividly purple ’82 Riviera with 105 horses of Oldsmobile diesel power under its hood, found in a Denver-area self-service boneyard recently.

Starting in the 1966 model year, the Riviera had been living on the same platform as the Cadillac Eldorado and Oldsmobile Toronado, both of which featured radical front-wheel-drive powertrains that used longitudinal V8s powering the front wheels via sturdy chains. However, despite the common platform, the Riviera alone kept the then-traditional front-engine/rear-drive setup, making it something of a corporate oddball for the next 12 years.

Then General Motors decided to downsize the Eldorado/Toronado platform for the 1979 model year, and the Riviera got those cars’ front-wheel-drive rig at the same time.

Sales of the smaller Rivvy were strong, no doubt due in large part to certain geopolitical events that sent gas prices skyward and caused fuel rationing and gas lines.

Back in the late 1970s and early 1980s, diesel fuel was much cheaper than gasoline in the United States. Mercedes-Benz and Peugeot had done reasonably well selling diesel-engined cars here during the 1970s, and so General Motors developed a diesel-burning version of the Oldsmobile 350-cubic-inch (5.7-liter) V8 engine. As was typical of naturally-aspirated automotive diesels of the time (every modern car’s diesel engine is turbocharged), horsepower was miserable but torque was strong; the engine in this car was rated at 105 horses and 205 pound-feet.

The 5.7 diesel first showed up in the Riviera for the 1981 model year. The base engine was a 4.1-liter version of the Buick V6, while the oil-burning Olds cost an extra $924 (about $3,206 in 2023 dollars). A comfortable and smooth-riding Riviera with the cheap fill-up price and long range of diesel sounded great, even if you had to line up with Freightliners and Peterbilts to get to a pump, but there were problems. Oh, so many problems!

Oldsmobile’s 350 V8 had been around since 1968 and it had proven to be both reliable and powerful. Oldsmobile’s engineers strengthened the 350’s block for diesel service, but they opted to save on production costs by keeping the gasoline engine’s cylinder head bolt quantity and locations. Because diesels run much higher compression ratios than gasoline-burners (in this case, the diesel Olds 350 had a 21.6:1 compression ratio while its gasoline counterparts had more like 8:1), the stresses on head bolts were correspondingly higher. Stretched and broken head bolts followed, with engine-destroying results.

On top of that, diesel fuel of the era was of irregular quality, and GM saved more bucks by omitting a water separator from the fuel system; this caused diesel-powered GM cars to cough to a halt with depressing regularity. The Oldsmobile diesels quickly earned a terrible reputation, and a tsunami of lawsuits washed over the company. Meanwhile, Cadillac’s variable-displacement V8-6-4 engine was having widely publicized troubles of its own, and the new Chevrolet Citation was in the headlines for recall after recall. It wasn’t a happy time for The General.

When GM developed a V6 version of the 350, the 4.3 Diesel, it didn’t suffer from most of the flaws seen in its big brother. The damage had been done, however, and the last year for the Olds diesel engines was 1985 (not coincidentally, gasoline prices crashed around that time).

This car had some interestingly futuristic bits and pieces that compensated somewhat for the troublesome engine. These emblems on the padded landau top used electroluminescent illumination, which looked cool (I’ve been unsuccessful in finding one of these lamps in working condition during my junkyard travels, but I’m not giving up).

These indicator lamps above the grille used fiber-optic cables for lighting. Later in the 1980s, Buick would install touchscreen displays (sourced from a supplier of ATM machine hardware) in Rivieras.

The landau top has been roasted by the Colorado sun, but otherwise this car is in fairly decent condition. I found registration documents inside that showed it had been operational as recently as a decade ago, so its owner managed to keep the diesel 350 working for many years.

The purple paint doesn’t appear to have been a factory color, but the high-quality painting of the door jambs and engine compartment indicate that a good paint shop did the respray.

The MSRP on this car with diesel V8 was $15,196, or about $52,721 in today’s money. Air conditioning, power windows and an AM/FM stereo radio were all standard equipment.