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 troubleshooting coolant leaks in a BMW 335i, it's crucial to adopt a methodical diagnostic approach. Start by inspecting the most accessible components, such as hose connections, which are often the culprits behind leaks due to looseness or wear. Next, examine the radiator and water pump for any visible signs of damage or failure, as these parts are known to fail and can lead to significant coolant loss. Pay special attention to the area on the driver's side between the radiator and the engine, where leaks frequently occur but may be difficult to spot. Additionally, don't overlook the vent hose connecting the upper radiator hose to the coolant reservoir, as this connection is particularly vulnerable to breakage. By systematically checking these areas, you can identify and address leaks early, preventing more extensive and costly repairs down the line.
When tackling coolant leaks in a BMW 335i, it's essential to understand the common problems that can arise within the cooling system. One of the most frequent issues is the failure of the water pump, which can lead to leaks due to wear and tear over time. Additionally, damaged or worn hoses are notorious for developing cracks or holes, resulting in coolant escaping under pressure. The radiator itself can also be a source of leaks, especially if it has been subjected to physical damage or corrosion. Another potential culprit is the thermostat housing, where gaskets can fail, allowing coolant to seep out. Lastly, severe head gasket issues can lead to significant coolant loss and require immediate attention. By being aware of these common problems, you can more effectively diagnose the source of a leak and take the necessary steps to fix it, ensuring your BMW 335i remains in optimal condition.
Addressing a coolant leak in your BMW 335i is not just a matter of routine maintenance; it is a critical step in safeguarding your vehicle's performance and longevity. Ignoring even a small leak can lead to severe engine overheating, which may result in catastrophic damage to vital components such as the engine block, cylinder heads, and gaskets. This kind of damage can escalate repair costs significantly, often running into thousands of dollars. Moreover, a coolant leak can compromise the efficiency of your cooling system, leading to inadequate temperature regulation and increasing the risk of engine failure. For DIY enthusiasts, early detection is key; regularly inspecting your coolant levels and monitoring for any signs of leaks can save you from extensive repairs down the line. By addressing coolant leaks promptly, you not only protect your investment but also ensure that your BMW 335i continues to perform at its best, providing you with a reliable and enjoyable driving experience.
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