How to Tell If you Have A BMW Coolant Leak

Do you think your BMW may have a coolant leak? A coolant leak is something that you want to get fixed right away. Continue reading for signs that you might have a coolant leak.

Your vehicle’s coolant can leak either inside the car or outside the car. A sweet smell inside your car can identify an internal leak. If you have an external coolant leak, you may see colorful fluid under your car. 

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How To Tell If Your BMW Is Leaking Coolant

If you are reading this article, you probably suspect that your BMW is leaking coolant. There are several signs that you can look out for to determine whether or not you have a coolant leak issue.

Below, we will cover some ways that you can identify a coolant leak without opening the hood of your car:

One of the simplest ways to tell if your BMW coolant is leaking is by looking under your car. If you see a colorful puddle underneath it, this means that you have an external coolant leak.

Standard coolant colors are:

  • Orange
  • Yellow
  • Red
  • Purple

1. Look For Steam

A more frightening sign of a coolant leak is when your hood starts to steam. If you see steam coming out of your car’s hood, this means that the coolant in the engine is boiling. In this instance, you need to pull over immediately. Also, it would be a good idea to call for roadside assistance so that no further damage is done. When the car is fixed, make sure your coolant is topped off. It probably evaporated in the steam.

2. Exhaust Smoke Is A Big Indicator

Another way you can spot a coolant leak is by paying attention to the exhaust pipe. If you see white smoke coming out of the exhaust pipe, this means your coolant has leaked underneath the hood. When this happens, the coolant is burned and gives off white smoke. This white smoke is then shot out of the pipe. It is not something that you will easily miss.

3. A Hot Engine

Is your engine hotter than normal? If you are unsure, pay attention to the dashboard’s temperature gauge the next time you drive your car. If your gauge keeps rising, or if it consistently stays at a hot temperature, this indicates that something is wrong; and a coolant leak could be causing the issue. If you notice the gauge rising or staying high while driving, you need to pull over and wait for the temperature to drop. Then go to a mechanic to check it out.

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4. Check The Dashboard Lights

Another way to spot a coolant leak is by looking at the check engine light on your dashboard. If this is on, and you are experiencing some other symptoms of a coolant leak, then this is an indicator that you are experiencing this issue.
Another indicator to pay attention to is your ‘low coolant level light’. If this turns on shortly after you refiled your coolant, this means your coolant is leaking.

5. Sniff Out The Issue

You can tell if coolant is leaking by using your nose. Coolant has a sweet smell to it. So, if you notice an unusually sweet odor in your car, you will want to take your vehicle in for a possible repair.

What To Do If You Experience These Issues

If you think you have one or more of these issues, you will want to address them immediately. Putting it off until later can result in severe damage to your car; in addition to this, driving around in a car that is overheating could be a potential threat to yourself and those around you. Unless you are a trained mechanic, you should bring your car into the shop for repair. That way, you won’t accidentally run into more issues.
BMW engine new coolant lines

How A Coolant Leak Is Diagnosed

Even if you have identified that your BMW has the symptoms of a coolant leak, someone will still need to open the hood and check the components to know for sure. The best option is to bring your vehicle to a certified mechanic, but if you are experienced and want to diagnose it yourself, here is how.

The way to diagnose a coolant leak is to find where the leak is coming from. That way, you know what part to repair. Before you begin, make sure you have a radiator pressure tester kit on hand.

Once you get this tester kit, follow these steps to find where the leak is coming from:

  • Wear safety glasses and make sure the engine is cool.
  • Find the fitting that fits your radiator.
  • Remove the radiator cap.
  • Fill up the coolant so that air doesn’t enter the system.
  • Tighten adaptor, so the fitting is snug in the radiator.
  • Attach the radiator pressure tester.
  • Remove the engine cover in case the leak is there.
  • Look at the radiator cap to see what pressure you need to set the system to.
  • Pump the system until it reaches the aforementioned pressure.
  • If there is a leak, you may not be able to get it to the desired pressure.
  • Alternatively, the gauge could slowly drop.
  • Look around the engine bay and locate where the coolant is leaking.

Common Areas that Coolant Leaks Occur

When you go through this process of pressurizing the system to find a leak, there are a few places in the engine bay that you will want to pay particular attention to.

Here, we will go over some components to pay attention to and the issues that they may be experiencing:

  • Radiator: Due to vibration, the upper and lower hose’s connection can fail, causing a leak. Internal corrosion could also cause a leak.
  • Hose: an old hose can sustain damage that results in a coolant leak.
  • Water Pump: Issues such as a bad shaft seal and a faulty gasket O-ring can cause the coolant to leak.
  • Head Gasket: a head gasket failure causes coolant to leak into a cylinder or the crankcase, diluting the oil.


If you have any of these symptoms or find the leak yourself, it is time to take your car to a mechanic.

Take Your Car into a Certified BMW Mechanic

If you are looking to save money, don’t take your car to a dealer to be repaired. Instead, go to a certified BMW mechanic!
BMW repair shops have more economical pricing than their BMW dealer counterparts. This is due to:

  • Parts: Independent mechanics use original equipment manufacturer (OEM) replacement parts, which often results in at least 20% savings.
  • Labor: BMW technicians often have a lower hourly rate than the dealership.

Also, you don’t have to worry about the warranty being voided due to avoiding the dealership. If the shop is BMW certified, your warranty will stay valid!


There are a plethora of ways to determine whether or not your BMW has a coolant leak.
If you discover that you have a leak or suspect that you have one, you need to take your car in for inspection and possibly repair. Without coolant, your vehicle will overheat and can damage your engine; and your engine is much more expensive to repair than a coolant leak.

So, get ahead of the leak, and get your car repaired. You will be back on the road in no time!

SL Autoworks


5 star service BMW Specialist

prices that always beat the dealer

Or Call: 501-214-1091

501 West 8th Street
North Little Rock, AR 72114