Engine overheating issues are a common complaint among many BMW owners. There are various reasons your vehicle can overheat and some of them are outlined below.
The first step to avoiding an overheat concern is to perform preventative maintenance. You should be performing cooling system fluid exchanges every 2 years (or every 30k miles) to have the best chance at keeping your coolant in working condition. For a BMW, it is critical to follow the manufacturer’s recommendations for coolant color. Most BMW’s require a blue colored antifreeze although you want to check your vehicle specifically to make sure you are within manufacturer’s specifications (you may find this in the owner’s manual).
You may find yourself driving down the road and see the coolant temperature needle dive into the red. Nooo! Please remember if you ever experience an overheating condition, it is best practice to shut the car off in a safe place as soon as possible. Turning off your engine can be the difference between a normal repair and replacing the entire engine.
In certain situations, you may see your engine beginning to rise to a temperature higher than normal and there are a few causes of this. I’d like to say I can predict any circumstance to prevent you from having a bad day, although there are more than a few causes that can occur (ie: coolant leaks, wrong coolant type, clogged cooling system, cooling fan malfunction, or even failed water pump/thermostat).
Your engine requires coolant to regulate the temperature of the engine. In the event you spring a leak in the cooling system, air forces its way into the system and interrupts coolant flow. This generally ends up being the issue in an overheated engine. Another way coolant flow can be interrupted is a clogged part in the cooling system. The thermostat, radiator and expansion tank are especially susceptible to clogging (especially if you’ve got a classic BMW). Proper coolant flow is important to keep the system running at an acceptable temperature.
The way we test for a customer concern of overheating generally starts with an array of questions to pinpoint possible causes (so be ready to talk!) and then we perform a cooling system pressure test. This will uncover any obvious coolant leaks and some that may have been tough to find with normal engine operation. There are deeper dives into a cooling system diagnostic that are performed when necessary. A good number of newer BMW’s have electric water pumps and these have function to activate them through professional scanners.
If you take one thought away from this article, I’d like you to remember that it is imperative to turn off your vehicle at the time of an overheat. Also, pay attention to the color of the warning light (or take a picture if safe to do so).