Engine

A suspected thermostat fault presents two choices: replace a part that may be stuck or check whether another cooling-system problem explains the symptoms.

Two coolants can look alike yet contain different corrosion inhibitors. Mixing them may leave deposits in the cooling system, restrict the heater core

A metallic ping during acceleration and a deep knock from the engine’s lower end can mean different things. The first may point to abnormal combustion

Coolant keeps disappearing, the temperature rises on a climb, or the engine misfires briefly after sitting overnight. Yet the ground beneath the car stays dry.

Replacing spark plugs can look like a simple remove-and-refit job. On a modern engine, a damaged cylinder-head thread, an incorrectly specified plug, or

A sharp tick or tapping noise on a cold start is one of the most recognizable signs of an exhaust manifold leak. You may also notice an exhaust odor under

A hard start, weak acceleration, or a rough idle can point to a compression problem. A home test may reveal a mechanical fault, but it can also produce

Engine oil additives promise quieter operation, lower oil consumption, improved compression, or even a restored engine. The difficulty is that finished

A turbocharger can fail after months of apparently normal commuting. A whistle, blue smoke, rising oil use, or an oil film in the intake may point to a

The starter turns normally, but the engine will not fire. A minute later, it starts as if nothing happened. Or the engine stalls after warming up and restarts