it's important to note that using stop leak products for your vehicle's heater core is generally considered a temporary and last-resort solution. They may be able to seal minor leaks, but they can also potentially cause damage to your cooling system in the long run. The best and most reliable way to fix a leaking heater core is to have it properly repaired or replaced by a qualified mechanic.
If you are experiencing a heater core leak, I strongly recommend visiting a reputable auto repair shop to have the issue diagnosed and repaired professionally. A skilled mechanic can assess the severity of the leak and provide you with appropriate solutions to fix it properly.
Using a stop leak product may lead to clogging other parts of the cooling system or cause issues down the line, so it's best to avoid relying on these products as a permanent fix. Remember, maintaining your vehicle's cooling system is crucial to avoid more significant problems in the future.