The coolant can leak into the engine and burn during combustion. When the head gasket fails on your BMW, you might not see any leaks, but you will keep losing coolant. Other Cooling System Issues Head Gasket Failure These lower hoses can be damaged by road debris or even from pulling into a parking spot too far and making contact with the curb. Some radiator hoses will be at the very bottom of the engine bay. In most cases, your radiator hoses should be replaced every 4 to 5 years or 50,000 to 60,000 miles. When they stop expanding and contracting like intended, they can split open or develop pin-sized holes in them. Since these hoses are made of rubber, they will degrade over time and become dry and brittle from heat and exposure to the elements. These seals can become dry and brittle over time, making them unable to hold pressure anymore. Another point of failure is the internal seal. The heat from your engine can cause this plastic housing to warp, resulting in a leak when the cooling system is under pressure. This housing is bolted to the engine assembly with a seal in it. Most BMWs have a housing made of plastic where the thermostat resides. Just like all moving parts, wear and tear from regular driving can cause your water pump to fail.

A belt or chain drives the water pump, and an internal impeller rotates while the vehicle runs. When your water pump begins failing, it can cause coolant to leak out of it. Coolant Leaking From The Water Pumpĭepending on the year and model of BMW you own, you should plan on replacing the water pump around the 80,000-mile mark. Another reason that coolant could be leaking from the reservoir is an improperly installed cap, it might appear to be tight, but if it was cross-threaded, it could leak as the pressure in the system rises. This means the cap can no longer hold the increasing pressure from the coolant as the temperature rises. Over time and through use, the internal spring can wear out. These reservoirs are sealed using a twist-off spring-loaded cap. Most BMW vehicles have a coolant reservoir attached in a remote location under the hood. If you are involved in a front-end collision, even a minor one with very little damage, the integrity of the radiator can become compromised and cause a leak. Sometimes the radiator will only leak when it’s at ambient temperature or when it reaches running temperature, while other times, it could always leak.Īnother common cause is road debris hitting the radiator and causing a leak where the damage occurred. Temperature changes can cause the metal and plastic parts to separate, causing a leak. Due to the changing temperature of your coolant, it will expand and contract the parts of the radiator very slightly. Most BMW radiators also have plastic end tanks attached on both sides. Radiators have multiple passages of metal hoses that the coolant travels through to lower the fluid’s temperature. The radiator on your BMW sits in the front of your car, ahead of the engine, and just behind your bumper. Read below for more in-depth information on these problem areas. It could be from a failed cooling system component, faulty coolant reservoir cap, or something more severe like a failed head gasket. There are multiple places where you could be losing coolant in your BMW. The most common places for your BMW to leak coolant are the radiator, coolant reservoir cap, water pump, thermostat housing, and radiator hoses.Ĭontinue reading for problematic areas where coolant leaks on BMWs often occur and likely causes. Do you see coolant on the ground where you park your BMW? Do you smell something unusual coming from the engine compartment after a drive? Is it normal for the coolant level to keep getting lower? Is your car suffering from an overheating condition? If you are unsure if your BMW is leaking coolant, keep reading to find out how to identify the problem and what to do next.

Oil in coolant resovoir m62