The radiator tank expansion may seem largely insignificant to your Mini overall, but when it fails, you will find out quickly that it’s a critical part of your car’s ability to run properly.

As a Mini owner, you have come to expect quality engineering and performance from your car, so it can be frustrating when something like a radiator tank expansion can bring all that down. Fortunately, there are some warning signs you can look out for to help you avoid a disastrous failure that could cost you a sizable sum of money to repair.

What does the radiator tank expansion do?

The coolant in your radiator will expand and contract in volume as it rises or lowers in temperature. The expansion tank is there to offer some extra space for that coolant as it expands. It is also known as an overflow tank. Having this expansion tank helps to avoid the pressure in your radiator growing too high and helps to keep your Mini engine working at the ideal temperature.

The Warning Signs When a Radiator Tank Expansion is Failing

Below are a few signs you can keep an eye out for to give you a heads up when your Mini’s radiator expansion tank has failed or is on its way to failing:

  • Low coolant levels can be a sign that your expansion tank is cracked or otherwise not sealed This will cause the radiator coolant to leak out as it moves through the system. You should check your coolant levels regularly to make sure you can catch such leaks early.
  • Finding coolant puddles under your car is a sure sign that you have a coolant leak somewhere, and the expansion tank is always a good place to start looking. Coolant fluid is often a bright color such as green, yellow, orange, or purple, and has a sweet aroma. If you are finding anything like this pooling under your car when it’s been parked for a while, it’s a sure sign you need to get it checked out.
  • If your engine is overheating, you likely have a coolant problem. As we mentioned above, when your expansion tank fails, in all likelihood you will be leaking coolan If your MINI’s engine is overheating, it could cause permanent damage that could leave you stranded roadside if you keep driving it in that condition. If you observe your engine overheating bring it to a shop ASAP.
  • If the radiator is getting rusty, you likely have a failed expansion tank. The reason is that that tank is what is supposed to keep your radiator from getting rusty to start with.

What are the causes of radiator expansion tank failure?

Take a look at a few reasons why your radiator expansion tank might have failed:

  • Normal wear and tear will eventually cause any auto part in your MINI to give out. The expansion tank could have simply worn out from use.
  • The expansion tank could have become cracked or damaged. This can happen in extreme external temperatures, or because the engine has become overheated in the past, or simply due to age.
  • If the radiator cap is not sealed properly, perhaps because it’s broken, it will lose the pressure it requires to keep the coolant flowing properly.
  • The radiator expansion tank may not be operating at the proper pressure, which in turn could cause the engine to overheat.

What should you do about a failed radiator expansion tank?

The simple answer to this question is to get it repaired as soon as possible. If you keep driving after the signs of a radiator expansion failure, you are just asking for your engine to overheat and eventually break down. An overheating engine might even start a fire in the car, which could be a disaster. While this is an extreme case, it is not unheard of, and even without that catastrophic outcome, you would still be looking at serious money to fix an engine that had operated at too high a temperature for an extended period.

When you observe any of these warning signs, it’s time to bring your MINI to us at Cerrone’s European in Redwood City, CA. Our highly-trained mechanics specialize in repairs and maintenance in all European-made cars, including but not limited to the MINI.

It is our standard to use the latest technology and tools to inspect and diagnose any issues with your MINI to recommend the best course of action. We will get you back on the road safely and comfortably so you can drive with confidence again. Call us today to schedule an appointment.