How to Troubleshoot a Leaking Radiator in a Mazda Miata

A leak in your Mazda Miata's radiator can be caused by previous damage that punctured the metal or by the effects of rust or metal corrosion. Either way, most radiator damage can be fixed using inexpensive commercial products. The simplest type of product works by using tiny particles that expand, sealing the hole from the inside. More serious damage will require an external radiator sealant to fill in the hole or crack.

Instructions

1

Start the engine and, with it idling, visually inspect the radiator to determine where the coolant is leaking. If the area is not too severely damaged, a leak-stopping solution designed for radiator use may be able to seal the leak.

2

Turn the engine off and allow it to cool. Remove the cap on the coolant tank. Pour in the contents of a container of radiator stop-leak, following the individual product's directions as to how much should be added. Replace the radiator cap, start the engine, and allow the Miata to idle for at least five minutes. Check the previously identified leak location to determine if coolant is still dripping out. If not, simply top off the coolant level and consider the repair complete. If it is still leaking, external repairs will be required.

3

Open a package of epoxy-based sealant designed to plug radiator leaks. Follow the product directions to activate the sealant. Liquid-based epoxies will require two parts, a resin and a hardener, to be mixed together, while putty-type epoxies will be activated through kneading.

4

Apply the sealant to the crack or hole in the radiator. Work it deep into the damaged area and allow it to overflow well beyond the edge of the actual damage to ensure a good seal. Let the product dry for the amount of time listed on the instructions. If necessary, fill up the radiator with antifreeze to replace any coolant that previously leaked out. Start the engine and visually inspect the damaged area to confirm it is no longer leaking.