The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.
When the head gasket begins to fail, the engine may have no symptoms at all. They only begin to occur when the leak has reached an engine oil passage, engine coolant passage or the engine cylinder.
When that happens, the engine may be very difficult to start, and run roughly when idling. There may be oil or coolant leaking, and the engine may begin to overheat, or at least run hot. At this point, there may be coolant in the engine oil pan — this will look creamy and lighter in color than the oil. Also, the radiator or engine coolant reservoir may have a gurgling sound, the presence engine oil, or smell of combustion. And the check engine light will come on.
The coolant being burned in the engine will produce white exhaust that smells sweet, like engine coolant. When the head gasket fails completely, the engine will overheat within minutes of starting, will stall and then won't restart.
A failing heater core may cause the car's interior to smell like engine coolant. The smell will become worse when the heater is turned on. The engine may also begin to run hotter until the vehicle is repaired.
The worst-case scenario is the engine overheating, which can cause extensive engine damage.
If the heater core is clogged, the air that blows when the heater is turned on will not be very hot.
Problems with the intake manifold gasket can create the following symptoms:
» LEARN MORE: Intake manifold gasket symptoms
A failing radiator can cause the engine to run hot or overheat. Most radiators are made of metal and plastic. The plastic parts can become brittle and crack over time, causing a leak of coolant (typically green or pink in color). All manufacturers have a recommended service interval for coolant renewal. As the coolant ages, the additives breakdown and being to form solid deposits. These deposits will build up in the passages of the cooling system and will eventually clog components, including the radiator. A leaking or clogged radiator must be replaced. Some automatic transmission cars will also have a transmission cooler integrated into the radiator. Lines going to and from the transmission circulate transmission fluid to help cool the transmission in heavy duty applications such as towing or off-roading. If this integrated cooler fails, it can allow transmission fluid and coolant to mix. This will causing shifting issues in addition to overheating.
A coolant leak may be noted from the hoses. Coolant hoses can be damaged by oil leaks, or age. This will lead to swelling or cracking, it is suggested to replace the hoses before they begin leaking to avoid potential overheating.
The bad thermostat can cause two different sets of problems, depending on whether it's stuck open or stuck closed.
A thermostat that is stuck open can cause the engine to run colder than normal and turn on the check engine light. It may also cause poor fuel mileage and the heater to blow cool air.
A thermostat that is stuck closed will cause the vehicle to overheat. If a new thermostat doesn't resolve engine temperature problems, the cooling system needs to be checked for other issues.
» LEARN MORE: Signs of a bad thermostat, and how to fix it
The two most common signs of a bad pump are leaks and noises.
Leaking water pumps can result in damage to the drive and timing belts, and cause the engine to overheat. A failed water pump can be caused by other problems in the cooling system, such as a bad thermostat, radiator or head gasket.
When tackling coolant leaks in your BMW 128i, start with a thorough visual inspection of the cooling system. Look for any obvious signs of leakage, such as wet spots or stains around hoses, the radiator, and the water pump. Pay close attention to the expansion tank, as cracks or damage here are common culprits. If you notice any coolant pooling under the vehicle, this can help you narrow down the source of the leak. Next, check the coolant level in the reservoir; a significant drop over a few days indicates an ongoing leak. If the initial inspection doesn’t reveal the issue, consider using a pressure tester to pressurize the cooling system, which can help identify leaks that are not visible under normal conditions. Remember to monitor the engine temperature closely during this process, as overheating can occur if the coolant level is critically low. By following this diagnostic approach, you can effectively pinpoint the problem and take the necessary steps to repair it, ensuring your BMW 128i runs smoothly and efficiently.
When dealing with coolant leaks in a BMW 128i, it's essential to understand the common problems that can arise within the cooling system. One frequent issue is the deterioration of rubber hoses, which can become brittle over time and develop cracks, leading to leaks. Additionally, the radiator itself may suffer from corrosion or physical damage, resulting in coolant escaping. Water pump failure is another critical concern; if the pump is not functioning correctly, it can cause coolant to leak from the weep hole or the pump gasket. Furthermore, blown head gaskets can create significant coolant leaks, often accompanied by symptoms such as overheating or white smoke from the exhaust. By being aware of these potential failure modes, DIYers can conduct thorough inspections and take proactive measures to address any issues before they escalate, ensuring the longevity and reliability of their BMW 128i's cooling system.
Addressing a coolant leak in your BMW 128i is not just a matter of routine maintenance; it is a critical step in ensuring the safety and longevity of your vehicle. Ignoring the signs of a coolant leak can lead to severe consequences, including engine overheating, which can cause irreversible damage to vital engine components. This not only compromises the performance of your car but can also result in costly repairs or even complete engine failure. The urgency of fixing a coolant leak cannot be overstated, as prolonged neglect can exacerbate the problem, leading to further damage to other engine parts. By taking immediate action to repair a coolant leak, you safeguard your engine's health, maintain optimal performance, and ultimately protect your investment in your BMW 128i. Prioritizing this issue ensures that your vehicle remains reliable and safe on the road, preventing potential safety risks associated with engine overheating.
Read about related problems experienced by other BMW 128i drivers like you.
See what others are asking about their BMW 128i. Get answers from RepairPal's community of auto experts and enthusiasts.