The BMW engines from this era, especially the inline-6 engines, are known for developing oil leaks due to aging gaskets and seals.

The cooling systems on older BMW models can become problematic due to radiator and water pump failures, leading to overheating.

Over time, the timing chain can stretch or wear, which can cause engine performance issues or even severe engine damage if not addressed.

The fuel delivery system, including components like the fuel pump and injectors, may become faulty, leading to poor engine performance or starting issues.

Older BMW engines often develop vacuum leaks due to brittle hoses, which can affect engine idle and performance.

The electrical systems in older BMW models can suffer from corroded connectors and failing wiring, leading to various engine management problems.

Older BMW engines, including the 1986 635CSi, are known for developing oil leaks over time, often from the valve cover gasket, oil pan gasket, or rear main seal.

The cooling system components such as the radiator, water pump, and hoses can wear out and fail, leading to overheating issues.

Electrical problems, including faulty wiring and malfunctioning sensors, can be common in older BMW models.

The timing chain and related components can wear out, causing rattling noises and potential engine damage if not addressed.

Issues with the fuel injection system, such as clogged injectors or a failing fuel pump, can lead to poor engine performance.

Vacuum hoses and seals can become brittle and crack, leading to vacuum leaks that affect engine performance and idle quality.

Engine mounts can wear out over time, leading to increased engine vibration and noise.

The exhaust manifold can develop cracks, leading to exhaust leaks and increased engine noise.

BMW engines from this era are known for developing oil leaks, especially from the valve cover gasket and oil pan gasket.

Older BMW models often have problems with the cooling system, including failing water pumps, radiators, and thermostat housings.

The timing chain and its associated components can wear out, leading to potential engine damage if not addressed.

Vacuum lines and gaskets can become brittle over time, leading to rough idling and performance issues.

Fuel injectors may become clogged or fail, causing misfires and poor engine performance.

The variable valve timing (VANOS) system can experience problems, leading to rough idle and loss of power.

Ignition coils can fail, causing misfires and engine performance issues.

A failing crankshaft position sensor can cause starting issues and engine stalling.

BMW engines from this era are known for developing oil leaks, especially from the valve cover gasket and oil pan gasket.

Older BMW models often have problems with the cooling system, including failing water pumps, radiators, and thermostat housings.

The timing chain and its associated components can wear out, leading to potential engine damage if not addressed.

Vacuum lines and gaskets can become brittle over time, leading to rough idling and performance issues.

Fuel injectors may become clogged or fail, causing misfires and poor engine performance.

The variable valve timing (VANOS) system can experience problems, leading to rough idle and loss of power.

Ignition coils can fail, causing misfires and engine performance issues.

A failing crankshaft position sensor can cause starting issues and engine stalling.

Common in older BMW engines, especially around the valve cover gasket, oil pan gasket, and rear main seal.

Often occur at the radiator, water pump, and coolant hoses due to aging components.

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

If not replaced at recommended intervals, can lead to severe engine damage.

Dirty or failing fuel injectors can cause poor engine performance and misfires.

Can lead to rough idling, stalling, and poor fuel economy due to aged hoses and seals.

Can cause the engine to stall or fail to start.

Aging wiring and connectors can lead to various electrical issues affecting engine performance.

Can cause coolant and oil to mix, leading to overheating and significant engine damage.

Worn or fouled spark plugs can cause misfires and reduced engine efficiency.

BMW engines, especially older models like the 1986 325/325e, are known for developing oil leaks from various seals and gaskets, such as the valve cover gasket and oil pan gasket.

The cooling system in these engines can be problematic, with common failures including the radiator, water pump, and thermostat, leading to overheating issues.

Over time, the timing belt (or chain, depending on the specific engine) can wear out or become loose, which can cause engine performance issues or even catastrophic engine failure if it breaks.

Vacuum hoses and intake boots can become brittle and crack with age, leading to vacuum leaks that can cause rough idling and poor engine performance.

The fuel injectors in older BMW models can become clogged or fail, leading to poor fuel economy, misfires, and reduced engine performance.

Older BMW models can suffer from various electrical problems, including faulty sensors, wiring issues, and failing engine control units (ECUs), which can affect the overall performance and reliability of the engine.

Common in older BMW engines, especially around the valve cover gasket, oil pan gasket, and rear main seal.

Often occur at the radiator, water pump, and coolant hoses due to aging components.

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

If not replaced at recommended intervals, can lead to severe engine damage.

Dirty or failing fuel injectors can cause poor engine performance and misfires.

Can lead to rough idling, stalling, and poor fuel economy due to aged hoses and seals.

Can cause the engine to stall or fail to start.

Aging wiring and connectors can lead to various electrical issues affecting engine performance.

Can cause coolant and oil to mix, leading to overheating and significant engine damage.

Worn or fouled spark plugs can cause misfires and reduced engine efficiency.

Common in older BMW engines, especially around the valve cover gasket, oil pan gasket, and rear main seal.

Often occur at the radiator, water pump, and coolant hoses due to aging components.

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

If not replaced at recommended intervals, can lead to severe engine damage.

Dirty or failing fuel injectors can cause poor engine performance and misfires.

Can lead to rough idling, stalling, and poor fuel economy due to aged hoses and seals.

Can cause the engine to stall or fail to start.

Aging wiring and connectors can lead to various electrical issues affecting engine performance.

Can cause coolant and oil to mix, leading to overheating and significant engine damage.

Worn or fouled spark plugs can cause misfires and reduced engine efficiency.

BMW engines from this era are known for developing oil leaks, especially from the valve cover gasket and oil pan gasket.

Older BMW models often have problems with the cooling system, including failing water pumps, radiators, and thermostat housings.

The timing chain and its associated components can wear out, leading to potential engine damage if not addressed.

Vacuum lines and gaskets can become brittle over time, leading to rough idling and performance issues.

Fuel injectors may become clogged or fail, causing misfires and poor engine performance.

The variable valve timing (VANOS) system can experience problems, leading to rough idle and loss of power.

Ignition coils can fail, causing misfires and engine performance issues.

A failing crankshaft position sensor can cause starting issues and engine stalling.

Common in older BMW engines, especially around the valve cover gasket, oil pan gasket, and rear main seal.

Often occur at the radiator, water pump, and coolant hoses due to aging components.

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

If not replaced at recommended intervals, can lead to severe engine damage.

Dirty or failing fuel injectors can cause poor engine performance and misfires.

Can lead to rough idling, stalling, and poor fuel economy due to aged hoses and seals.

Can cause the engine to stall or fail to start.

Aging wiring and connectors can lead to various electrical issues affecting engine performance.

Can cause coolant and oil to mix, leading to overheating and significant engine damage.

Worn or fouled spark plugs can cause misfires and reduced engine efficiency.

BMW engines from this era are known for developing oil leaks, especially from the valve cover gasket and oil pan gasket.

Older BMW models often have problems with the cooling system, including failing water pumps, radiators, and thermostat housings.

The timing chain and its associated components can wear out, leading to potential engine damage if not addressed.

Vacuum lines and gaskets can become brittle over time, leading to rough idling and performance issues.

Fuel injectors may become clogged or fail, causing misfires and poor engine performance.

The variable valve timing (VANOS) system can experience problems, leading to rough idle and loss of power.

Ignition coils can fail, causing misfires and engine performance issues.

A failing crankshaft position sensor can cause starting issues and engine stalling.

Older BMW engines, including the 1986 635CSi, are known for developing oil leaks over time, often from the valve cover gasket, oil pan gasket, or rear main seal.

The cooling system components such as the radiator, water pump, and hoses can wear out and fail, leading to overheating issues.

Electrical problems, including faulty wiring and malfunctioning sensors, can be common in older BMW models.

The timing chain and related components can wear out, causing rattling noises and potential engine damage if not addressed.

Issues with the fuel injection system, such as clogged injectors or a failing fuel pump, can lead to poor engine performance.

Vacuum hoses and seals can become brittle and crack, leading to vacuum leaks that affect engine performance and idle quality.

Engine mounts can wear out over time, leading to increased engine vibration and noise.

The exhaust manifold can develop cracks, leading to exhaust leaks and increased engine noise.