Common Warning Signs of Coolant Leak in Your BMW


The coolant is an important part of your BMW. It is responsible for helping keep the radiator, and therefore the engine, from overheating while you drive. BMW owners can top off the coolant on occasion if it runs out after prolonged driving. But if the coolant seems to run out quickly or there are other warning signs of a coolant leak, then consider visiting a reputable BMW repair shop to diagnose the problem and get repairs.

Car owners of a BMW need to recognize the common signs of coolant leaking in their car. This will ensure they make it to a licensed mechanic to fix the problem right away before it damages your BMW.

Common Signs of Coolant Leaking

Car owners will notice several common signs when coolant starts to leak from their BMW. Some of the more noticeable signs include:

  • Overheating: When the coolant runs out, there is no refrigerant to keep the engine from overheating. A car owner should look at the temperature gauge to see if the BMW tends to overheat. If it does seem warm, call a mechanic right away. The longer the overheating occurs,the more damage it causes to the engine.
  • Coolant Light: This is an obvious sign that something is wrong with the coolant. When that light comes on, you should consider how long it has been since you added more fluid. If you did that recently, then you may have a coolant leak in your BMW.
  • A blue liquid pool: BMW coolant fluid is often blue in color. If you look under the car and notice a blue liquid pooling, then this points to leaking coolant. If it is hard to tell what color the liquid is, see if there is a sweet smell. Coolant has a sweeter smell compared to gasoline or oil.
  • Your BMW breaks down: This is a sign that you ignored the coolant for too long and the BMW has been overheating for some time. You will face extensive repairs at this point.

Reasons for Coolant Leaking

BMW owners may notice that there are different reasons why the coolant leaks out of their car. The leak can potentially come from a few different locations in the car and different mechanical failures may be
the cause.

In most BMW’s, the expansion tank is made out of plastic. While plastic is cheap to use, it is not always durable. Plastic can easily crack compared to other materials and when it does, the coolant fluid can leak out. If the expansion tank does crack, you will need a certified mechanic to replace the whole thing.

In some cases, the pipes that connect to the radiator can wear out. If they are not replaced in time, they may break. The coolant has to travel to the radiator to keep the BMW from overheating. If there are no pipes to connect the coolant tank to the radiator, the coolant will leak right out of the vehicle.

What happens if the coolant runs out?

Car owners who drive their BMW on low or no coolant will cause severe damage to their BMW's engine. Prolonged overheating can also cause the radiator to fail. Since the BMW radiator is made out of aluminum, which is only slightly more durable than plastic, it has more potential to break. This damage may be expensive to repair as you may need a rebuild.

If you notice any signs of the coolant leaking, you need to get your BMW checked out as soon as possible. The issue may be small, but ignoring it can turn a simple solution into a major problem that will cost a lot of money. A certified mechanic can take a look at the BMW to check whether there is a leak in the coolant and get the problem fixed so you can be on your way.

M Service for Your BMW Needs

At M Service in Walnut Creek, CA, we are happy to help our customers with all of their BMW repair needs. Our certified technicians can handle any coolant leaks that occur in your BMW so your car is safe to drive. Call us today to set up your appointment. We look forward to meeting with you and serving you as a repeat customer soon.  

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BMW Repair
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