Symptoms
- Coolant drips from underneath the water pump, often visible from below the front of the engine
- Coolant level dropping gradually
- Possible whining or grinding noise from the pump area
- Overheating if the leak becomes severe or the pump fails completely
Likely causes
- CommonWorn internal seal (weep hole leak)This seal wears over tens of thousands of miles and is designed to leak through a small weep hole rather than internally when it fails.
- CommonWorn or damaged gasket where the pump mounts to the engineGasket material can degrade or the gasket can be damaged during a previous installation.
- PossibleCorrosion pitting the pump housingOld or wrong coolant can corrode the pump housing itself over time.
- PossibleBearing failure alongside the sealThe bearing supporting the pump shaft often fails around the same time as the seal, adding noise to the leak.
What to do
- Look underneath the front of the engine, near where the serpentine belt drives various components, for a small steady drip or crusty residue.
- Check for any noise from the pump area, like a grinding or rough bearing sound, which suggests the bearing is also failing.
- Check the coolant level and top off temporarily while arranging a repair.
- Avoid extended driving if the leak is more than a slow weep, since sudden pump failure can cause rapid coolant loss and overheating.
- Have a mechanic confirm the water pump is the source, since leaks can sometimes be mistaken for a nearby hose.
- Replace the water pump, which is often done along with the timing belt on engines where the pump is driven by that belt, since labor overlaps significantly.
- Flush and refill coolant properly after the repair and check for leaks after a short test drive.
Tools and parts
- Flashlight
- Gloves
Water pump and gasketSearch: “water pump for [make model year]”
When to call a pro
See a mechanic for water pump replacement, since it usually requires draining coolant, removing belts, and sometimes more extensive disassembly depending on the engine.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.