An overheating engine can be a scary experience for any BMW owner. Unfortunately, this is a fairly common complaint that can have several different causes.
Often, strange noises are one of the first signs that your BMW’s engine is overheating. The following guide provides some insights into what causes these unusual sounds and a few of the issues you may be dealing with.
Common Noises Associated with Engine Overheating
Aside from the engine temperature warning light, strange noises are one of the primary indicators that you’re dealing with an overheating engine. Thumping noises are often associated with a thermostat failure, which causes a BMW’s coolant to become superheated. The thumping sound occurs when this extremely hot coolant mixes with cold coolant coming from the vehicle’s radiator.
A distinct ticking sound can also be a sign of engine overheating. This is caused by the engine’s oil losing viscosity due to the high heat. When this happens, the oil becomes too thin to lubricate the moving parts properly. The resulting ticking, clicking, or clanking sound is caused by moving parts inside the engine hitting each other.
If you turn your BMW off and wait a few minutes, you may also notice a hissing sound. This is caused by liquids or fluids touching the hot engine. Sometimes, you’ll also be able to see visible steam coming from the engine area. This is a good sign that either a specific part or your entire engine is overheating.
What Causes BMW Engines to Overheat?
There are several possible issues that can cause a BMW’s engine to overheat. Some are fairly easy to fix while others require expensive and time-consuming repairs. Here’s a look at some of the most common problems our technicians encounter when dealing with overheated BMWs.
Cooling System Leaks
Engines require coolant to keep them running at optimal temperatures. If your BMW’s coolant system has a leak, the levels will eventually get too low for it to function as it should.
Colored puddles under your vehicle are a common sign of a cooling system leak. You may also notice a sweet smell coming from your BMW after you shut it off. Sometimes, this is an easy fix – like tightening a loose clamp or replacing a hose. Other times, it can require a complex repair.
Your BMW’s thermostat regulates the flow of coolant through the engine. If it gets stuck open or closed or the part fails altogether, this can cause the engine to overheat. In most cases, when there’s a problem with the thermostat, your check engine light will come on.
BMW thermostats can fail for a variety of reasons, including a build-up of deposits or a failed seal. Coolant leaks can also lead to thermostat failure. Luckily, this is a fairly easy fix that can be done in a couple of hours.
Failed Water Pump
Your water pump circulates coolant through the engine, helping to keep it at an optimal temperature. BMWs use an electric water pump, rather than a traditional mechanical pump. While this can create superior performance, they also typically need to be serviced or replaced at about 80,000 miles to avoid expensive problems down the road.
In addition to basic wear and tear, water pumps can also be affected by coolant leaks or exposure to old coolant. If you notice that your BMW is frequently running hot or overheating, this could be a sign of a water pump failure. It’s important to take care of this issue right away before you have to deal with engine problems.
If your BMW’s radiator is clogged, the coolant won’t be able to flow into the engine properly and your vehicle will frequently run hot. It’s common for this to happen as dirt and debris build up over time.
You may also notice coolant leaks, low coolant levels, or that your coolant has taken on a rust color. It’s important to take care of a clogged radiator as soon as possible to prevent further damage to the radiator or costly engine repairs.
Incorrect Coolant Type
To ensure optimal performance, BMW engines require a special type of coolant that has a specific viscosity level. It’s critical to make sure you’re using the right coolant for your BMW’s engine, otherwise, you may find that your engine overheats.
You can find the information you need in your owner’s manual or consult with one of our technicians if you’re not sure which type of coolant is right for your vehicle.
What to Do if Your BMW Overheats
If your BMW begins to overheat, turn off your air conditioning and turn the heat up as high as it will go. This can help divert heat away from the engine until you can pull over in a safe place.
Once you’ve stopped the vehicle, let it cool for at least 15 minutes, then check the coolant level. If the level is low, top it off, as this can temporarily protect your engine and prevent overheating until you can get your BMW to a trusted service center.
Remember that seeking help as soon as possible can help you avoid expensive engine damage. If you’ve noticed unusual sounds and an engine that’s running hot, now is the time to have your vehicle serviced.
The experts at The Haus can quickly diagnose the issue, repair your BMW, and get you back on the road! Contact us today to schedule your VIP appointment.