Vehicles using 4G16 engine list:

Engine 4G16

Symptoms:
- Rough idling or stalling during low RPM
- Difficulty starting the engine, especially when cold
- Reduced engine power and poor acceleration
- Excessive oil consumption or visible oil leaks
- Overheating or unusual engine temperature fluctuations

Diagnosis:
- Check for vacuum leaks around intake manifold and hoses, which can cause rough idling
- Inspect spark plugs and ignition components for wear or fouling, leading to misfires
- Examine carburetor or fuel injection system for clogging or improper adjustment affecting fuel delivery
- Look for oil leaks around valve cover gasket, oil pan, and seals
- Test cooling system including radiator, thermostat, and water pump for proper operation to prevent overheating

Fixes:
- Replace cracked or brittle vacuum hoses and gaskets to restore proper air-fuel mixture
- Clean or replace spark plugs and ignition wires to ensure reliable ignition
- Service carburetor jets or fuel injectors; adjust fuel mixture and idle speed as per manufacturer specs
- Repair or replace leaking gaskets and seals; change engine oil and filter regularly
- Flush cooling system, replace faulty thermostat or water pump, and ensure radiator is clean and free of blockages

Prevention:
- Perform regular maintenance including timely oil changes and spark plug replacements
- Use quality fuel and keep the fuel system clean to avoid clogging
- Inspect and replace aging rubber components such as hoses and belts before failure
- Maintain cooling system with periodic coolant changes and system checks
- Follow manufacturer’s recommended service intervals to detect and address issues early

This approach helps maintain the 4G16 engine’s reliability and performance in Mitsubishi Colt/Mirage and Lancer/Mirage models from 1986–1988.