What Is a Car Engine Overhaul and When to Do It

What is an Engine Overhaul?

A car engine overhaul is usually done when there are serious problems with a car and its engine. During an overhaul, your mechanic disassembles the engine and then evaluates the condition of the internal components to identify the source of the problems and fix them. Internal parts such as the piston rings, bearings, gaskets, and camshaft may be replaced during an overhaul, though it depends on their condition and what the source of the problem is.

• A drop in engine performance
• Cracked, leaking, or broken engine components
• A reduction in engine oil levels even when no leaks are detected
• Frequent overheating of the engine

Top Overhaul

There are two types of engine overhaul – a top overhaul and a full overhaul. A top engine overhaul is when the top half of the engine is opened without extracting the whole engine from the engine bay. This process is often done when the problem parts are easier to reach and replace. Common parts replaced during a top overhaul include the cylinder head and head gaskets, valves, valve seal, cylinder screws, and rocker arm.

Full Overhaul

A full engine overhaul is when the whole engine is removed from the car and disassembled. In a full overhaul, the sources of the problems are often hard to reach, hence the need to remove the whole engine. This process requires more time and labor to complete, which is why it costs more than a top overhaul. Common parts replaced during a full overhaul include the crankshaft, piston rings and rods, engine block, bearings, timing belt/chain set, and other necessary parts.

What Is the Cost of a Top and Full Overhaul?

The cost of a car engine overhaul varies widely depending on the issue, the parts that need replacing, and the type of overhaul done. The cost of a top overhaul for Proton and Perodua cars typically costs around RM800 to RM3,000. On the other hand, the cost of a full overhaul for the same models could start from RM4,000 and above. That said, a proper estimated cost can only be determined after a thorough check on the engine is done.

When Should You Overhaul Your Car Engine?

While some engine issues do not need an overhaul to be fixed, there are times when it’s necessary. An engine overhaul is also more commonly needed on older cars, especially ones over 10 years old or when a car has racked up a lot of mileage. If you notice these problems with your car or if your warning lights turn on for a prolonged period, it’s best to get your car checked so you don’t have bigger problems down the road.