Two of the most common parts to fail on a high-mileage engine are the water pump and the ignition coil. Catch them early and the fix is cheap and simple. Ignore them and you risk an overheated engine or a no-start. Here are the warning signs to watch for.

Water Pump Warning Signs

1. Coolant leaks under the engine

A puddle of green, orange or pink coolant near the front-center of the engine often points to a worn water pump seal. The Gates 44039 engine water pump is a direct-fit replacement for the Jeep Grand Cherokee 3.6L V6.

2. Engine overheating

If your temperature gauge climbs, a failing pump may no longer be circulating coolant. Continued driving can warp the cylinder head. See all options in our Water Pumps collection.

3. Whining or grinding from the front of the engine

A worn pump bearing makes a high-pitched whine that changes with engine speed. That bearing can seize, so do not wait.

Ignition Coil Warning Signs

4. Rough idle, misfires and a check-engine light

A weak coil delivers an inconsistent spark, causing a shaky idle, hesitation and misfire codes (P0300-P0306). The Denso 673-1307 ignition coil is an OEM-quality coil-on-plug replacement for 2.4L Toyota, Lexus, Scion and Pontiac engines.

5. Poor fuel economy and lost power

When a cylinder is not firing cleanly, the engine works harder and burns more fuel. Replacing a failing coil restores smooth power and efficiency. Browse the full range in our Ignition Coils collection.

Fix Small Problems Before They Get Big

Both repairs are far cheaper than the engine damage they prevent. Match the correct part number to your vehicle and replace the part early. Explore our Water Pumps and Ignition Coils collections to find the right fit.