BMWs are popular around the world for their understated luxury and class, not to mention their powerful yet smooth driving experience. However, a major setback for any driver is an issue with an overheating engine, which can stop your driving experience. The most frequent cause of overheating is a leaking coolant. In this article, we will take a closer look at why this issue occurs and how to best deal with this problem, should it happen to you and your BMW.
Coolant is usually a bright color, often pink or green, and it smells sweet. It is also known as antifreeze. Coolant is a mixture of distilled water and alcohol. The primary role of this liquid is to absorb the heat from a running engine. It does this by entering the engine block via a reservoir affixed to the radiator. The coolant continually cycles, absorbing heat then being cooled back down by the radiator.
The secondary role of coolant is to prevent freezing. This is particularly handy for drivers living in cold areas. It is the prime reason why antifreeze consists of alcohol, not just water. If your coolant was solely water-based, then it could freeze within your vehicle, causing all manner of damage.
As coolant is brightly colored, it is usually pretty easy to spot when you have a leak. However, if you want to make sure that the leak is definitely coolant, testing is easy. All you need to do is place a piece of cardboard under your BMW and leave it there overnight. In the morning, study the type of leak, the color, and its location. If you notice the drops are dark yellow or brown in color, then you have an oil leak and not a coolant leak. If the liquid appears clear, then it’s more than likely transmission fluid.
There are two key causes of coolant leaks. Being aware of these will help you to diagnose a leak and discover its source.
If the radiator develops holes or even a hairline crack, then coolant will be able to leak out of the system. This also means the correct pressure will not be kept within the system. This will also impact the effectiveness of the radiator, meaning that warm coolant might circulate through the engine instead. This will impact your engine’s performance as well as increasing the risk of overheating, since coolant is not circulating properly. There are several reasons why holes or cracks may occur in your BMW’s radiator. The most common is corrosion that occurs over time, usually due to poor maintenance. However, holes can also be caused by damage caused when driving, such as rocks or debris hitting it, as your radiator is situated at the very front of your car behind the grill. This makes it easily damaged.
The leading cause of internal coolant leaks is a faulty or bad head gasket. The chief role of the head gasket is to keep the coolant system closed; ergo, preventing coolant from getting where it shouldn’t. Therefore, if the head gasket isn’t working properly, then coolant will escape the system. The coolant will usually make its way into the crankcase or into a cylinder, where it will mix with the engine oil, causing contamination and significant damage. If the coolant is able to reach the spark plugs, it will burn, resulting in white smoke exiting through the exhaust pipe.
There are many reasons why the head gasket can fail, such as damage that has been caused when your BMW has overheated.
The best way to deal with a coolant leak in your BMW is to avoid it entirely. To avoid that, be sure to perform routine maintenance and servicing on your vehicle at the appropriate times. This will ensure that should problems occur, they are dealt with quickly, preventing further damage and further expense to you.
Pro Car Mechanics is on hand to help those living in or around Gardena, Long Beach, Los Angeles, Glendale, or Anaheim, CA communities with any BMW’s repair and maintenance needs. Our staff are professional and friendly, and our technicians are specialists in foreign and imported vehicles. When it comes to your prized BMW, nothing will be overlooked by our experts. Let us become your trusted BMW mechanics.