Q: After changing radiator and oil, car stalls when coming to stop. Is the motor damaged?

Hello. Stalling can be caused by many things. If the engine is no longer overheating, then it is unlikely that the stalling is directly related to the radiator repair. A few common causes for stalling when braking are a faulty idle air control valve or vacuum leaks. The idle air control valve is the component responsible for maintaining and adjusting the engine’s idle speed.

If the valve fails or malfunctions, it can cause idle issues and stalling. The same for a vacuum leak. A vacuum leak, if large enough, can cause stalling. Another thing to check, if the issue appears to be brake related, is the brake booster, as this component is vacuum-operated and can also leak. It may also be possible that a hose or tube came loose, if any of the intake tubes, or vacuum hoses had to be removed when replacing the radiator. I would start by checking the engine for vacuum leaks and then looking at the idle air control valve.

If you need assistance, then I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the car is stalling and suggest any necessary repairs.