Yes, replace the expansion valve and valve cores. Valve cores are the weakest part. Now, you can brass plug to install over leaking cores. The brass plugs work better than plastic caps. I've used plugs on domestic cars but not on my X5. Flush it good with a can of A/C flush. Use compressed air to clean out hoses and evaporator. My system goes down to 40F/4C on the highway. Sometimes even on the lowest blower motor speed, I have to turn it off. It's super cold!

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'06 X5 3.0i - bought @143,123 miles (12/26/20)