Engine

The temperature rises in traffic or on a long climb, and you have to decide quickly whether to stop, add coolant, or keep moving. The same warning can

A hybrid’s gasoline engine may shut off in traffic and run less often than the engine in a conventional car. It still needs oil, filters, coolant, spark

A rebuilt engine needs a deliberate break-in because new rings, cylinder surfaces, bearings, and valve-train parts must establish working contact.

An intermittent shake or a brief loss of power can make an ignition coil seem like the obvious purchase, especially when a misfire code names one cylinder.

Variable valve timing problems are system problems, even when the scan tool displays a code associated with one solenoid. A hydraulic VVT system uses an

Two bottles marked 5W-30 may meet the same viscosity grade and still suit different engines. A motor can also sound different after an oil change, even

The engine dies at a stoplight, then restarts easily a few seconds later. Sometimes the Check Engine light stays off, which makes the fault harder to interpret.

A falling coolant level with no puddle beneath the car is frustrating, especially when the engine bay looks dry. A visible drip gives you a place to start.

A metallic tick that persists after warm-up can prompt a valve-clearance check. So can an engine that sounds quiet but starts poorly when cold.

Finding oil beneath the pan after a repair is frustrating, especially when a new gasket has just gone in. The pan is one of the lowest parts of the engine