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 diagnosing a coolant leak in your 2007 BMW 335xi, it's essential to adopt a systematic approach that begins with the simplest checks before moving on to more complex diagnostics. Start by checking the coolant level in the reservoir or radiator; a low level often indicates a leak. Next, conduct a thorough visual inspection around your vehicle for any puddles or traces of coolant, as these can provide immediate clues to the leak's location. Pay special attention to the coolant reservoir for any signs of discoloration or low levels, which may suggest a leak. Additionally, examine all coolant hoses and clamps for any visible damage, such as cracks or loose connections, which are common culprits. The radiator should also be inspected, particularly around seams and core areas, as these are frequent sources of leaks. If you observe steam or smoke emanating from the engine, this could signal a more serious issue that requires prompt attention. Lastly, be aware of potential head gasket problems, which can lead to significant coolant leaks; symptoms include engine overheating and unusual oil appearances. By following this structured diagnostic approach, you can effectively identify and address coolant system issues, ensuring the longevity and performance of your BMW 335xi.
When dealing with coolant leaks in a 2007 BMW 335xi, it's essential to understand the common culprits that may be at play. One of the primary sources of leaks can be damage to the radiator, which is positioned at the front of the vehicle and is susceptible to impacts and corrosion over time. Additionally, worn hoses are a frequent issue; as they age, they can become brittle and develop cracks, leading to leaks in the cooling system. Another potential problem is a failing water pump, which can leak coolant if it is not functioning correctly. It's also important to check the thermostat gaskets, as these can deteriorate and cause leaks from the thermostat housing. Lastly, severe head gasket issues can lead to significant coolant leaks and should be addressed immediately to prevent further engine damage. Regularly inspecting your vehicle for puddles or stains, monitoring the temperature gauge, and examining the cooling system components can help you identify these issues early, allowing for timely repairs and maintenance.
Addressing a coolant leak in your 2007 BMW 335xi is of utmost urgency, as neglecting this issue can lead to severe engine damage and costly repairs. Coolant is essential for regulating your engine's temperature, and a leak can disrupt this balance, resulting in overheating. If the engine overheats, it can cause significant harm, including warped cylinder heads or a blown head gasket, which are expensive to fix. Additionally, a persistent leak can lead to a complete engine failure, leaving you with a hefty repair bill and the inconvenience of being without your vehicle. Therefore, if you notice any signs of a coolant leak, such as puddles under your car or a drop in coolant levels, it is crucial to investigate and resolve the issue immediately to ensure the longevity and reliability of your BMW 335xi.
See what others are asking about their BMW 335xi. Get answers from RepairPal's community of auto experts and enthusiasts.
Read about related problems experienced by other BMW 335xi drivers like you.
