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
If a vehicle is overheating, a bad thermostat could be the problem, and a damaged thermostat housing is more likely to produce a coolant leak, either from a cracked or warped housing or a failed seal to the engine. The thermostat housing can be made of metal or plastic. And the housing can be a stand-alone part that is separate from the thermostat, or (on later model vehicles) can be integrated with the thermostat and replaced as a single unit.
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 Mercedes-Benz E350, start with a thorough visual inspection of the coolant reservoir and surrounding components. Look for any signs of leakage, such as puddles or wet spots, which can indicate where the coolant is escaping. Pay close attention to the coolant level; if it drops significantly without any apparent reason, this could signal a leak. Additionally, monitor your dashboard for any warning lights related to coolant levels, as these alerts can provide early indications of a problem. Common culprits for leaks include worn water pumps and damaged hoses, so be sure to check these components carefully. If you suspect a water pump issue, listen for unusual noises that may precede visible leaks. Once you identify the source of the leak, you can determine whether a simple hose replacement or a more complex repair is necessary. By following this methodical approach, you can effectively diagnose and address coolant leaks, helping to maintain your vehicle's performance and prevent overheating.
When tackling coolant leaks in a Mercedes-Benz E350, it's essential to understand the common problems that can arise within the cooling system. One frequent issue is the failure of the water pump, which can lead to significant coolant loss if not addressed promptly. Additionally, worn-out hoses and clamps may develop cracks or become loose over time, contributing to leaks. Radiators can also corrode or sustain damage, resulting in coolant escaping from the system. It's crucial to inspect these components thoroughly during your diagnosis. Look for signs of coolant pooling under the vehicle or on engine parts, and pay attention to any unusual sounds that may indicate a failing water pump. By being aware of these common failure modes, you can more effectively pinpoint the source of the leak and take the necessary steps to repair or replace the affected parts, ensuring your vehicle remains in optimal condition.
Addressing a coolant leak in your Mercedes-Benz E350 is not just a matter of routine maintenance; it is a critical step in safeguarding your vehicle's performance and longevity. Ignoring even a minor coolant leak can lead to severe overheating, which poses a serious risk to the engine and can result in costly repairs. The cooling system is vital for maintaining optimal engine temperature, and any disruption in coolant flow can lead to reduced efficiency and drivability. Moreover, a coolant leak may signal deeper issues within the cooling system, such as damaged hoses or a failing water pump, which, if left unaddressed, could escalate into more significant problems. By prioritizing the repair of a coolant leak, you not only protect your investment but also ensure the safety and reliability of your vehicle on the road.
Read about related problems experienced by other Mercedes-Benz E350 drivers like you.
See what others are asking about their Mercedes-Benz E350. Get answers from RepairPal's community of auto experts and enthusiasts.
