An engine failure can turn into a financial nightmare. Your options are limited to fixing the assembly or replacing it; both solutions are expensive. If the cost of repairing or replacing it exceeds the value of your vehicle, the only sensible option may be to retire your car. On the other hand, if your car is still roadworthy, a new (or overhauled) engine may be the best decision.
Whatever path you choose, it’s important to identify the underlying reasons your engine failed in the first place. Otherwise, a replacement may develop the same problems. Below, we’ll take a look at the most common causes of failure: overheating, spark knock, and insufficient motor oil.
Most people fail to realize how delicate their car’s engine is. There are many factors that can cause it to overheat. For example, if your radiator lacks coolant due to a leaking hose or radiator cap, pockets of steam can develop. If a thermostat fails, a cooling fan might fail to turn on. Or, the bad thermostat may fail while closed, which will prevent coolant from reaching the radiator.
Another factor that can cause your engine to overheat is your radiator developing a clog from accumulated sediment and corrosion. Or, the air-fuel mix might lean out, causing the operating temperature of your engine to rise.
When the assembly overheats, a number of secondary problems can occur. Because metal expands in higher temperatures, overheating can cause valves to stick, pistons to freeze up, and the cylinder heads to warp. These are the reasons an overheating engine usually represents a large repair bill.
Spark knock is also referred to as detonation. This occurs when excess heat builds within the combustion chamber and forces an abnormal ignition of the compressed air-fuel mixture. It sounds like a knock. Over time, detonation can lead to cracked rings, blown out head gaskets, and even holes in the pistons (the knocking sound is caused by a blow sustained by the piston).
There are a few factors that can cause spark knock. For example, if the exhaust gas recirculation (EGR) system fails, the air-fuel mixture can become too rich while the temperature in the combustion chamber rises. Other causes include a too-lean mixture, poor ignition timing, and consistent use of low-octane gasoline.
As you know, your engine requires oil for the lubrication of its moving parts. Without oil, the friction created between those parts can quickly lead to failure. Sometimes, this is caused by neglect. Many people simply forget to check the oil level in their engines. Other times, the level can decline due to a leak in a seal or gasket, or a failing oil pump. If you notice oil leaks, have them fixed as soon as possible.
Because engine failure is so expensive, it’s worthwhile to have a mechanic perform routine checks. In doing so, you may be able to avoid having to overhaul or replace the assembly before its time.