What was found
OIL COOLER IS PART OF A CERTIFIED ENGINE INST ON A CE-172M. DURING CRUISE FLIGHT, THE OIL COOLER RUPTURED IN THE AREA OF THE END TANK ON THE OUTPUT SIDE OF THE COOLER. THIS CAUSED A RAPID LOSS OF OIL AND ENGINE FAILURE. ON-AIRPORT LANDING WITHOUT FURTHER DAMAGE. IT IS SUSPECTED DURING MFG OF THIS PART, THE SOLDER FLUX WAS NOT THOROUGHLY CLEANED FROM THE TANK WHICH CAUSED A THINNING OF THE METAL.