BMW Repair & Service

Why is My BMW Engine Overheating?

BMW engine overheating issues are a common complaint among many BMW owners. Some of the main causes of overheating in BMWs include coolant leaks, a clogged coolant system, water pump failure, and using the wrong type of coolant. To correctly diagnose the symptoms, it’s important to have your car inspected by a certified, professional mechanic who is an expert at repairing and maintaining these finely tuned driving machines.

Symptoms of a BMW Engine Overheating

If you drive a BMW and are worried about your car’s engine overheating, keep an eye out for the following symptoms.  If you notice any of these signs, we recommend taking your car to a certified BMW maintenance facility at the earliest opportunity.

Engine Overheating Light

The BMW engine overheating warning light is designed to give drivers an accurate reading of engine temperature.  If an engine exceeds the maximum safe temperature for the operation of your vehicle, the engine overheating light turns on.  You can also check the temperature gauge, which indicates excessive engine heat by rising above the red or hovering near the top of the gauge.

Thumping Noises

If you notice strange thumping sounds coming from your vehicle, engine overheating could be the cause.  Thumping sounds could be caused by a malfunction in the thermostat which regulates the flow of coolant between the radiator and the engine. Failure of this thermo sensor causes the coolant in a BMW engine to become superheated, which then makes a thumping noise as it mixes with the cold coolant coming from the radiator.

Engine Ticking Sound

A ticking noise can be another warning sign your BMW engine is overheating. A BMW engine is lubricated with a protective layer of engine oil. When the oil becomes too hot, it loses viscosity and is too thin to properly act as a lubricant, which causes the moving parts of the engine to make a distinct ticking sound.

Hood is Hot to the Touch or Steam Coming from Under the Hood

One of the easiest ways to identify an overheating engine is to touch the hood. If it is too hot to touch after 10 seconds, the engine is likely overheating.  Another clear indicator of BMW engine overheating is steam escaping from under the hood. This occurs when the coolant inside the reservoir starts to boil, causing steam to be released.

Causes of Engine Overheating

Some of the most common BMW overheating causes include:

Engine Coolant Leak

Every internal combustion engine requires coolant to keep the engine temperature at optimal levels.  If your coolant system has sprung a leak, your car’s engine is most likely not receiving an adequate amount of coolant for it to function properly.  If you suspect a coolant leak, check the ground under your car for wet spots; this could be an indication that your BMW is losing coolant.

Coolant System Restriction

BMW engine overheating issues can also be caused by a restricted cooling system. Over time, debris and natural dirt buildup can prevent coolant from circulating through the engine properly, causing the engine to overheat.  A malfunctioning thermostat can also lead to overheating.

Malfunctioning Water Pump

Engine overheating can also be caused by a faulty water pump.  Water pumps are crucial in maintaining the correct engine temperature by ensuring adequate coolant circulation. BMW water pumps usually need to be serviced or replaced on a regular basis.

Incorrect Coolant Type

BMW engines require a specific type of coolant to function at optimal performance levels and prevent engine overheating. Each BMW model requires a coolant with a specific viscosity for its unique engine design. For more information on choosing the best coolant to prevent your BMW engine overheating, check your owner’s manual, or contact a BMW service center.

How to fix BMW Engine Overheating Issues?

If you suspect your BMW engine is overheating, your most reliable option is to contact an experienced BMW technician or service center. Cooling system maintenance and repair is best done by a seasoned professional who can accurately diagnose the engine overheating cause, whether it is from a coolant leak, worn water pump, malfunctioning engine cooling fan, or something as simple as a broken radiator cap.

BMW owners in the South Orange County area trust the technicians at Star Motors. Residents have voted our shop as the Best Auto Repair in Orange County for 11 years in a row. Don’t wait until you’re stranded on the side of the road with an overheated engine. Make an appointment online or give us a call if you suspect any engine issues or want to follow up with routine maintenance services.

Frequently Asked Questions

What happens if you drive with an overheated engine?
Driving with an overheating engine is dangerous! Excess engine heat can cause radiator hoses and seals to weaken and break, releasing coolant and antifreeze. Driving with an overheated engine can also cause warped cylinder heads, which can lead to a blown head gasket, one of the most expensive repair jobs for BMWs. Welds, seals, belts, and wiring can also be compromised and can cascade into severe damage to the steering column and fuel pump.

How do I know if my BMW is overheating?
One of the surest ways to detect BMW engine overheating in San Juan Capistrano, CA, is if your car’s engine temperature light comes on, or if the temperature gauge rises into the red zone. Other signs include thick white smoke coming from the exhaust system, unpleasant odors seeping through the AC vents, and fluid leaks under your parked car. You might also notice that your hood is hot to the touch, steam coming from under the hood, clicking noises or thumping, and/or decreased engine performance.

How do I stop my engine from overheating?
Regular maintenance from a trusted BMW maintenance service center is the first step to preventing BMW engine overheating. Some other effective preventative measures include:

  • Pay attention to your car’s engine overheating warning light and temperature gauge!
  • Keep on top of your coolant levels and watches for signs of leaks.
  • If your coolant levels are low, make sure you add the correct type of coolant for your BMW engine.
  • Get a radiator flush. Servicing your radiator clears out any old coolant and antifreeze, which can be contaminated with debris that clogs cooling systems.
  • Replacing your old thermostat with a high-performance version is an inexpensive fix.