One thing all BMW owners can agree to is the fact that BMWs are wonderful cars. Another thing they will also agree with, although grudgingly is the fact that BMWs require proper and frequent maintenance of the engine cooling system if the car is to maintain its efficiency. Albeit a wonder product of the German automaker, BMWs are regularly plagued with the problems of a failed cooling system leaving the engine in serious jeopardy.
The essence of an engine cooling system is to keep your engine running at an optimum and consistent temperature. There is no one part of the engine that is called the ‘cooling system’, it is essentially a collection of components each performing its own unique task towards maintaining an optimal engine temperature. These parts include; the coolant, radiator, thermostat, water pump, radiator cool fan, cooling hose and cooling system pressure cap.
The most common sign of a failed cooling system is overheating. If you notice a rise in the temperature gauge of your car, especially when the increased level is in the red zone or smoke emitting from underneath the bonnet, then there is a good chance your engine is overheating. Emission of thick fumes from your exhaust pipe could also mean that your cooling system is faulty. The coolant is a sweet smelling greenish liquid designed to keep the engine cool, lubricated and rust free. Now, a coolant leak which would be noticed under the car is also a warning sign of a faulty cooling system.
Every component of your BMW engine cooling system is relevant and the slightest malfunction of any part could bring the entire system down. A leak in the coolant hose, a malfunctioning thermostat, a blown head gasket allowing the coolant to flow into the combustion chamber, a clogged radiator preventing dissipation of heat, failure of the water pump to circulate the coolant and low coolant levels are all some of the problems which could cause your BMW engine to overheat, an apparent sign of an engine cooling system failure.
It is pertinent to address cooling system issues as soon as they happen to avoid further damage to the engine. When you bring your BMW to us suspecting a failed cooling system, the first thing we do is to open the hood of your car and allow the engine to cool. Then one after the other, we begin to check all the components of the cooling system to determine the root cause of the problem. For the radiator, we will check both the outside and inside for debris and clog which could prevent the flow of heat. An internal clog may mean replacing the radiator, however, external debris can just be cleaned off. To check the radiator cooling fan, we simply turn on the engine and wait for it to warm up. Then we inspect the fans for movement, how fast the fans are rotating or if they are rotating at all. If the fans are faulty, then the fan clutch will have to be changed.
If the thermostat is bad, we can usually tell from checking the temperature of the lower and upper radiator hoses while the engine is running. In this case, the hoses are meant to be hot and if one or both hoses are cold, then we will replace the thermostat, and in some cases, the radiator hoses as well. To detect a faulty water pump, we leave the engine running and open the cooling system pressure cap. If the coolant is not moving around in the system like it should, then the water pump is failing and the engine needs a new one. No engine cooling system check is complete without checking for coolant leakages. We may add coolant dye to the system for easier spotting of a leakage if nothing is immediately detected.
In most cases, the fault can be detected from these tests, however, we can carry out further testing using unique diagnostic tools if we suspect an internal engine problem. Nevertheless, it is always in your best interest to perform regular servicing on your BMW. Sometimes the problem could just be from age and distance covered. These components have an expected lifespan and if you want to lengthen the lifespan of your BMW, you should try not to outwear the parts before replacing them.