That Temperature Gauge Is Climbing — Now What?
You're stuck in traffic on a hot afternoon when you notice it: your temperature gauge is pushing past the halfway mark and heading toward the red. Your heart rate spikes. Steam starts curling from under the hood. And suddenly you're that car on the shoulder with the hazards on, watching everyone else drive by.
Engine overheating is one of the most stressful — and potentially expensive — problems a car owner can face. A single overheating event can warp a cylinder head, blow a head gasket, or seize your engine entirely. We're talking thousands in repair bills from something that often starts as a $50 part failure.
The good news? Most cooling system problems give you warning signs before they become disasters. Here are six common failures to watch for — and what to do about them.
1. Failing Water Pump
Your water pump is the heart of the cooling system. It circulates coolant through the engine block, radiator, and heater core thousands of times per day. When the pump starts failing, circulation slows or stops completely.
Watch for: Coolant leaks near the front-center of your engine, a whining or grinding noise from the pump bearing, or steam from the radiator area. Some vehicles also show a visible wobble in the pump pulley.
Water pumps typically last 60,000-90,000 miles, but they can fail sooner — especially if the coolant hasn't been maintained. If yours is going, don't wait. A seized water pump can snap your timing belt and cause catastrophic internal engine damage.
2. Stuck Thermostat
The thermostat is a simple valve that opens and closes based on coolant temperature, controlling flow between the engine and radiator. When it sticks closed, coolant can't reach the radiator to cool down. When it sticks open, your engine runs too cold (which hurts fuel economy and increases wear).
Watch for: Temperature gauge that shoots to hot within minutes of starting the car (stuck closed) or never reaches normal operating temperature (stuck open). Erratic temperature readings are another red flag.
3. Leaking or Clogged Radiator
Your radiator does the heavy lifting of heat exchange — hot coolant flows in, air passes through the fins, cooler coolant flows back to the engine. Over time, radiators develop pinhole leaks from corrosion or get clogged internally from old, contaminated coolant.
Watch for: Puddles of green, orange, or pink fluid under your car after parking. Discolored or rusty-looking coolant. Temperature climbing in stop-and-go traffic but staying normal at highway speeds.
4. Blown Radiator Hoses
Upper and lower radiator hoses carry coolant between the engine and radiator. They're made of rubber that degrades over time from heat cycling, becoming soft, swollen, or brittle. When a hose bursts, you lose coolant fast.
Watch for: Soft, squishy hoses when you squeeze them (engine cool). Visible cracks, bulges, or white residue around hose clamps.
5. Bad Radiator Fan or Fan Clutch
The radiator fan pulls air through the radiator when the car is moving slowly or sitting still. When the fan doesn't engage, the radiator can't shed heat at low speeds.
Watch for: Overheating in traffic or at idle that goes away at highway speed.
6. Leaking Heater Core
The heater core is essentially a small radiator inside your dashboard. When it leaks, you lose coolant slowly — and the signs are often inside the car.
Watch for: A sweet smell inside the cabin. Fogging on windshield that won't clear. Wet carpet on the passenger side.
Don't Wait for the Steam
Every one of these problems is cheaper to fix as a part replacement than as an engine rebuild. At Pardical Auto Parts, we carry OEM cooling system components at prices well below dealer cost. Browse our eBay store with free shipping on most items.