The Toyota MR2 from this era, especially with the 5S engine, is known for developing oil leaks around the valve cover gasket and oil pan due to aging gaskets and seals.

The cooling system in the 1993 MR2 can sometimes struggle, especially if the radiator or thermostat is old or not functioning properly, leading to potential overheating issues.

The 5S engine uses a timing belt which requires regular maintenance. If not replaced at recommended intervals, it can lead to engine performance issues or serious damage if it fails.

With age, engine mounts can deteriorate, leading to increased engine vibrations and noise during operation.

The electronic fuel injection system and components like the distributor, ignition coils, and spark plugs may wear out or fail, causing misfires or starting difficulties.

A known issue in older engines like the 5S is head gasket failure, which can cause coolant leaks and engine overheating if not addressed.

Engine oil leaks can occur from the valve cover gasket, oil pan gasket, or other seals, leading to reduced oil levels and potential engine damage if not addressed.

Over time, the timing belt or chain may wear out or become misaligned, which can lead to poor engine performance or severe engine damage if it breaks.

The engine may experience overheating due to issues with the radiator, water pump, or thermostat, which can lead to engine damage if not resolved.

Problems with spark plugs or ignition coils can cause misfiring, leading to reduced engine performance and increased emissions.

Electronic fuel injection systems can develop problems such as clogged or leaking fuel injectors, which can lead to poor fuel economy and engine performance issues.

Vacuum leaks can occur in the intake manifold or other components, causing rough idling, stalling, or poor acceleration.

Faulty sensors, such as the oxygen sensor or mass airflow sensor, can lead to incorrect fuel mixture adjustments and affect engine performance.

Low-quality fuel or incorrect ignition timing can cause knocking or pinging sounds, which can lead to engine damage over time if not corrected.

Common in older engines, often due to worn gaskets or seals.

Can be caused by a failing thermostat, water pump, or clogged radiator.

Often due to issues with spark plugs, ignition coils, or fuel injectors.

If not replaced periodically, can lead to severe engine damage.

Issues with sensors or the fuel pump can cause poor performance or stalling.

Common in older engines, leading to oil leaking onto the exhaust system.

Can lead to exhaust leaks and reduced engine performance.

Can be caused by dirty throttle body, faulty idle air control valve, or vacuum leaks.

The 1991 Toyota MR2 with a 5S engine model is known to suffer from oil leaks, particularly around the valve cover gasket and oil pan due to worn gaskets and seals.

This model can experience overheating issues often due to a failing radiator, water pump, or thermostat. The cooling system components may be prone to wear and tear over time.

The 5S engine is susceptible to head gasket failures which can lead to coolant leaks, engine overheating, and loss of compression.

The timing belt in the 1991 MR2's 5S engine needs regular replacement, as failure can result in severe engine damage.

Issues with the electronic fuel injection system can arise, such as faulty sensors or clogged fuel injectors, leading to poor fuel economy and engine performance.

Problems with the ignition components, such as the distributor cap, rotor, spark plugs, and ignition wires, can cause misfires, rough idling, and starting problems.

The 1991 Toyota MR2 with a 5S engine model is known to suffer from oil leaks, particularly around the valve cover gasket and oil pan due to worn gaskets and seals.

This model can experience overheating issues often due to a failing radiator, water pump, or thermostat. The cooling system components may be prone to wear and tear over time.

The 5S engine is susceptible to head gasket failures which can lead to coolant leaks, engine overheating, and loss of compression.

The timing belt in the 1991 MR2's 5S engine needs regular replacement, as failure can result in severe engine damage.

Issues with the electronic fuel injection system can arise, such as faulty sensors or clogged fuel injectors, leading to poor fuel economy and engine performance.

Problems with the ignition components, such as the distributor cap, rotor, spark plugs, and ignition wires, can cause misfires, rough idling, and starting problems.

The 5S engine in the 1991 Toyota Celica may experience overheating issues due to age-related wear and tear on the cooling system, such as a failing radiator or water pump.

Common in older engines, oil leaks can occur due to degraded seals and gaskets, particularly around the valve cover, oil pan, and crankshaft seals.

The 5S engine uses a timing belt, which can wear out over time and require replacement to prevent catastrophic engine damage.

With electronic fuel injection, issues such as clogged or malfunctioning fuel injectors can cause poor engine performance and reduced fuel efficiency.

A known issue in older 4-cylinder engines, head gasket failure can lead to coolant mixing with oil, causing engine overheating and severe damage if not addressed.

Problems with spark plugs, ignition wires, or the distributor can lead to misfires, rough idling, and difficulty starting the engine.

Vacuum hoses and fittings can deteriorate over time, leading to vacuum leaks that result in poor engine performance and erratic idling.

The Exhaust Gas Recirculation (EGR) valve can become clogged or fail, leading to increased emissions and potential engine performance issues.