Description Reviews MINI Cooper Heater Core for all Gen 1 cars. This will fit the R50/R53 MINI Cooper & S 2002-2006, and the R52 MINI Cooper & S Convertible 2005-2008. If you see or smell coolant leaking in the cabin of your MINI, it is very likely your heater core has sprung a leak. It's not the most common, but we have seen it from time to time, here at the shop. Additionally, if you’re not getting heat, there is a very good chance that your heater core is plugged up and needs to be replaced. We also highly recommend a good flush on the the rest of the system as well. Our heater core kit comes with new pipe o-rings, clamps and a seal to fix the job correctly, the first time! Don’t forget to get some quality fluid on hand before you start the job!