Q: How to remove and install an oil cooler on Mercury Mariner?
A: Oil coolers are used only on 2007 and earlier models. To remove the oil cooler, raise the vehicle and place it securely on jack stands. Drain the engine coolant and the engine oil. Remove the oil filter. For four-cylinder models, disconnect the two coolant hoses from the oil cooler and remove the oil cooler mounting bolt. Detach the oil cooler from the engine block and install a new 0-ring. The installation is the reverse of removal.