bwm coolant warning light

BMW Coolant Light Comes On and Off (Solved & Answered)

BMWs are really fun to drive. They handle great, rear-wheel-drive accelerate extremely fast and are very comfortable in every type of environment. But, every car has its own little quirks, and BMWs are no different. One of the problems that many people have with BMWs is the Coolant light.

It seems to be a somewhat common problem that randomly comes on and stays on until it decides to go off. Once this happens, a lot of people don’t know what they should do or what’s wrong with their vehicle.

In this article, I am going to give an answer to what causes a coolant light to come on and off on your BMW so read on!.

BMW Coolant Light Comes On and Off Causes

The number one cause for the coolant light to come on and off on your BMW is a failing coolant sensor, if the light comes on and off and when you check your expansion tank there is coolant then it’s likely the sensor is damaged. Other causes include low coolant, wrong coolant type, and leak in the cooling system in your BMW car.

1. Bad Coolant Sensor

If the coolant light comes on and you find out the coolant is still full, it means the coolant sensor might be bad. The sensor measures the level of the coolant in your expansion tank and sends a signal to the computer to turn on or turn off the light.

If the coolant light comes on and you find out the coolant is still full, then you should check the coolant sensor. The sensor may be faulty, and it may not be sending a good signal to the computer. The easy way to tell is if you check your water bottle and the coolant is still full while the coolant light keeps coming on and off.

Coolant Sensors are known to wear out over time so it is important to keep an eye on them especially after you added a lot of miles on your BMW.

2. Coolant Below the Required Level

The coolant sensor is located inside the coolant expansion tank. If the coolant level is below the sensor, it can trigger the low coolant warning light. If you have recently topped it up, give it a few minutes for the fluid to settle and try again.

There are a couple of things that could cause the coolant to go down faster than anticipated including leaks and cracks, if the coolant is below the required level, top it up and switch the car on.

3. Wrong Antifreeze Used

BMWs are picky when it comes to coolant type, and you should always make sure that your vehicle is filled with BMW coolant.

Many people think that their cars will not be affected if they use a different brand of antifreeze, but this is not correct (especially with BMWs) as other brands may have different chemical compositions that can damage the engine, or cause the sensor to malfunction.

BMW specifies a special coolant with a high boiling point, low freezing point, and a specific ratio of water and antifreeze. The wrong coolant can damage the cooling system as well as cause the engine to overheat. The right coolant is necessary to keep the engine from running hot and triggers the coolant sensor.

Make sure you use the correct coolant (Blue in the cooler) that is made for BMW cars or a brand that is recommended by BMW.

4. Leak in the Cooling System

One cause of the BMW coolant light coming on and off is there is a leak in your BMW cooling system: the most common place to check is the water bottle itself (expansion tank), Check the pipes and the radiator. One very common cause of a leaking BMW radiator is when a plastic pipe connection at the bottom of the radiator cracks or breaks.

5. Low Battery Voltage (Uncommon)

This is a common cause of many warning lights coming on temporarily. If your BMW’s battery has been disconnected recently or is low because of a fault, this can cause the symbol to light up until voltage returns to normal levels.

Can You Drive a BMW with Low Coolant?

You can technically drive a few miles with low coolant, but doing so is dangerous. Your engine will begin to overheat and the temperature gauge will shoot up.

This causes damage to the engine and can cause your car to fail. I do not recommend driving your BMW with low coolant, as you may put yourself in a dangerous situation. Instead, fill your car with coolant as soon as possible.

How Long Can You Drive BMW with the Coolant Light On?

It is not recommended to drive the coolant light on in the first place, however, in case of an emergency and there is still some coolant in the water bottle then you can drive 5-15 minutes to get you somewhere safe.

What to do if your BMW Coolant Light Comes on While Driving?

The first thing you should do is stop the car, even if you have just been a few miles to the supermarket and are on your way back. It will be best to park somewhere safe and out of the way of traffic. Once you have stopped, check the coolant level in the tank.

If it is low, add some more coolant or water if you don’t have any with you. Remember, never open a hot cap of a radiator as it can cause burns

. Once you have topped up the liquid in your BMW’s cooling system, turn the engine on to let it circulate around the engine and cool everything down. Then drive to the nearest auto store.

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