The other big problem with the old 5.7 is it couldn't fight it's way out of a wet paper bag.
Haha.... yeah, at only 120 HP and later reduced to 105 HP, they weren't known for massive acceleration...
The biggest problem with the 5.7 diesel was head bolts. Don't believe the legend that they simply slapped new heads on the standard block. The new block was reinforced and was built of a sturdier cast-iron alloy, but blocks weren't really the problem. Most of the trouble came from the head bolts and the fuel system.
Diesel engines have more and stronger head bolts to compensate for the diesel's higher cylinder pressure. The Oldsmobile diesel maintained the same 10-bolt pattern and head bolts as gasoline engines, so that common production tooling could be used for both the gasoline and diesel engines.
The insufficient head bolts stretched or broke and led to head-gasket failures. Once the head gasket was breached, coolant leaked into the cylinders, and because clearances in a diesel engine are so tight, invariably this lead to hydrolock and severe engine damage.
One of the cost-reduction choices was to omit a water separator in the fuel system. During that time period, water-contaminated diesel was quite common, and high-quality diesel systems then and now include a water separator that, no surprise, remove water from the fuel. Diesel systems are highly susceptible to rust and any other corrosive elements. Without the water separator, corrosion was common in the Olds diesels' injection pumps, fuel lines and injectors, and that caused failed injection pumps and other maladies.
So....owners also took a page out of the gasoline engine owner's playbook and dumped anhydrous alcohol (also known as dry gas) into their fuel tanks to alleviate the water problem. Dry gas chemically bonds with water and puts it back into the gasoline solution, which allows it to pass through the engine without issue. But in the Olds diesel, the dry gas also ate the fuel pump seals and other delicate components.
There were certainly other issues with the engine.... a stretchy fuel-pump timing chain and poor dealer service training....which I went through in an 8 hour class.
The Oldsmobile 5.7 diesel was a hurry up answer to the increasingly stringent federal emissions and fuel-economy regulations that began in 1972, which diesels were exempt from at the time. Unfortunately it was just the wrong answer.
Years later we took a 5.7 Olds diesel block and modified it to work as a block for a race engine. It worked very well until the rules changed allowing us to use after market blocks.
