Using stop leak for an external leak could even worsen the situation. The product might clog smaller passages, further hindering coolant flow and potentially causing overheating or damage to the engine.
Instead of stop leak, you need to find and fix the source of the leak. This requires a visual inspection of the entire cooling system:
* Hoses: Check all radiator hoses, heater hoses, and connections for cracks, bulges, or loose clamps. Replace any damaged hoses.
* Radiator: Look for leaks around the radiator itself, especially at the seams or where the tanks connect to the core. A radiator leak might require repair or replacement.
* Water pump: Inspect the water pump for leaks around the shaft seal.
* Thermostat housing: Check for leaks around the gasket.
* Engine block: Look closely for cracks or corrosion in the engine block, which is more difficult to detect and often requires professional repair.
* Radiator cap: A faulty cap can cause pressure buildup, leading to leaks elsewhere in the system.
To find the leak:
1. Clean the engine: Thoroughly clean the engine compartment to remove dirt and grime that might obscure leaks.
2. Run the engine: Let the engine run for a while (with appropriate safety precautions) and observe carefully for leaks. You may need a helper to look while you run the engine.
3. Pressure test the cooling system: A pressure test will pinpoint the location of smaller leaks that might be difficult to see visually. This is best done by a mechanic.
In short: Don't use stop leak. Find and fix the actual source of the leak to prevent further damage and ensure the safety and reliability of your vehicle. Take it to a mechanic if you can't locate the leak yourself.
