While the vast majority of diesel engine problems can be fixed, there are cases where the damage is so severe that a replacement is the only tenable option. If the engine block is cracked, for example, or if a thrown conrod is poking through the block, you’ll almost certainly need a new engine. Such major engine damage is often preceded or accompanied by certain problems, such as significant power loss. Let’s take a quick look at some of the signs showing a diesel engine is damaged beyond repair.
Major Power Loss
Minor power loss is a cause for concern, but it can usually be fixed; major power loss is a different problem altogether and may be a sign that you need to replace your diesel engine. Several problems can cause major power loss, including a cracked or warped engine block and extensive damage to the exhaust system. Such problems are best solved by replacing the engine; it is easier and cheaper.
Sudden Increase in the Amount of Metal Shavings in Motor Oil
It is normal for motor oil to collect dirt and grime, including a small quantity of metal shavings, as it courses through a diesel engine. However, a sudden increase in the amount of metal is a sign of trouble – it means your engine is experiencing accelerated wear and is a surefire indicator of damage. Worse, the shavings can, in turn, cause even more damage because they impair the flow of oil and scour or gouge bearings, crankshaft journals, and other metal parts. The damage can get to the point where the only option is to replace the engine.
Serious Overheating
Constant, serious overheating is to diesel engines what kryptonite is to Superman – power-sapping and destructive. If it is not remedied in good time, overheating can wreck your head gasket, damage your exhaust manifold and cause your engine block to crack. In particularly serious cases, some components will melt. Because it is expensive – and in some instances, impossible – to repair such extensive damage, replacing the engine is usually the best option.
Closing Thoughts
Other signs showing a diesel engine is damaged beyond repair include knocking sounds, particularly if they get louder when you rev; very poor fuel economy; and an engine that continues running after you switch off the ignition. If you notice these signs (or anything else that seems out of the ordinary), visit an auto repair shop pronto.