In one particularly exciting MacGyver episode, our improvisational hero found himself with a shot-up radiator in his only method of escape. After obtaining some eggs from a nearby chicken coop, he pours the egg whites into the radiator to patch the hole. As the saying goes, truth is stranger than fiction. It turns out the egg-white trick is a viable method of temporary radiator repair. Just don't count on egg whites to repair your leaky radiator for good.
Leave your engine running. If your car is off, turn the engine on and let it warm up for a few minutes. The water in your radiator needs to be hot for this method to work.
Crack open an egg. Carefully remove the egg yolk, and pour the egg white into your cup. If you don't have a cup on hand, any container will do.
Repeat Step 2 with three more eggs.
Carefully remove the radiator cap. Wrap the towel around the cap, put on your gloves and slowly unscrew the cap until steam begins to issue from your radiator. Use caution, as this steam can be very hot. When the steam dissipates, unscrew the cap completely and set it to the side.
Pour the egg whites into the radiator. As the gooey egg whites enter the hot radiator, they will circulate through the internal tubes, thicken as they cook and wedge into any cracks.
Replace the radiator cap, close the bonnet and drive to a mechanic.
Some car enthusiasts say that black pepper works as well. The pepper works into the cracks and expands when it comes in contact with water.
This is a temporary fix. Take your automobile to a mechanic as soon as possible to receive suitable (and permanent) radiator repairs.