Mechanical Failures:
* Worn-out engine components: This is the most common cause. Over time, parts like piston rings, connecting rods, crankshaft bearings, camshaft lobes, and valve seals wear out. This leads to decreased compression, oil leaks, and ultimately engine failure. Lack of proper maintenance accelerates this process.
* Lack of lubrication: Insufficient oil (low oil level or oil pump failure) leads to catastrophic engine damage due to metal-on-metal contact.
* Overheating: A malfunctioning cooling system (radiator, water pump, thermostat, fan) can cause the engine to overheat, warping cylinder heads, cracking engine blocks, and damaging gaskets.
* Timing belt/chain failure: If the timing belt or chain breaks, the valves can collide with the pistons, resulting in severe engine damage. This is especially devastating in interference engines, which is common in many Blazer engines.
* Rod knock: This refers to a knocking sound caused by a connecting rod bearing failure. Ignoring this will lead to complete engine seizure.
* Camshaft wear: Worn cam lobes can lead to poor valve operation and reduced engine performance, eventually leading to failure.
* Internal leaks: Leaks in the cooling system or oil system can cause overheating, lubrication problems, and eventually engine failure.
Other Factors:
* Neglect and lack of maintenance: Regular oil changes, coolant flushes, and inspections are crucial to prevent premature engine wear.
* Previous damage: An accident or previous engine damage that wasn't properly repaired can lead to future problems.
* Low-quality parts: Using inferior-quality parts during repairs can lead to premature failure.
* Severe driving conditions: Excessive towing, off-road driving, or consistent high-RPM operation can put extra stress on the engine.
* Fuel system problems: A faulty fuel pump, clogged fuel injectors, or contaminated fuel can lead to engine misfires and eventual damage.
Specific to the 1999 Chevy Blazer: The specific engine (4.3L V6, 5.7L V8, etc.) will influence the likelihood of certain failures. For example, the 4.3L V6 is known for potential issues with the intake manifold gaskets and the cooling system.
In short: Pinpointing the exact cause requires a proper diagnosis by a mechanic. They would inspect the engine for signs of wear, leaks, and other problems to determine the root cause of the failure. Simply saying "the engine went out" doesn't provide enough information. The symptoms leading up to the failure are crucial in diagnosing the problem.
