1. Visual Inspection (Most Important):
* Radiator: Carefully inspect the radiator for cracks, leaks, or loose connections at the top and bottom hoses. Look closely at the radiator's lower tank, as this is a common area for leaks to appear near the tire well.
* Hoses: Examine all hoses connected to the radiator, water pump, and engine. Look for cracks, bulges, kinks, or areas where the hose clamps are loose or rusted. Pay special attention to the lower radiator hose, as its proximity to the tire well makes it a prime suspect.
* Water Pump: The water pump is located on the engine block near the timing belt. Check for any leaks around its housing or weep holes. This is more challenging and may require some disassembly.
* Thermostat Housing: The thermostat housing can crack or develop leaks around the gasket. Look for wetness or staining.
* Heater Core Hoses: While less likely to cause a leak *directly* by the tire, a heater core leak *could* drip down and accumulate near the wheel well if the leak is substantial and the vehicle has been driven for a while.
* Freeze Plugs (Core Plugs): These are located on the engine block. They can rust and leak, but this is less common near the tire.
* Power Steering Fluid Reservoir: Make absolutely sure it's coolant and not power steering fluid leaking. They are somewhat close.
2. Pressure Test:
This is crucial. A visual inspection may not reveal small leaks. A radiator pressure test kit from an auto parts store allows you to pressurize the cooling system and pinpoint leaks much more effectively.
3. Consider these less likely but possible causes:
* Cracked Engine Block or Cylinder Head: This is a serious and expensive issue. A pressure test often reveals this, but it's less likely to manifest *only* as a leak near the tire.
* Radiator Support: Damage to the radiator support from an accident could have compromised a hose or radiator.
Tools you might need:
* Gloves
* Safety Glasses
* Rags
* Flashlight
* Screwdrivers (Phillips and flathead)
* Pliers
* Radiator pressure test kit
* Hose clamps (if needed)
* New hoses (if needed)
* New thermostat or water pump (if needed)
Important Considerations:
* Type of Coolant: Note the color of the coolant. This can help identify the source (some power steering fluid can look similar to coolant).
* Smell: A sweet, somewhat syrupy smell is often associated with coolant. A burnt smell might indicate overheating.
* Location of Leak: Try to precisely locate where the leak is originating from. Take pictures if necessary.
If you're not comfortable working on cars, take it to a mechanic. A misdiagnosed coolant leak can lead to engine damage. The sooner you address the problem, the better.
