1. The Easy Checks (Do these FIRST):
* Coolant Level: Check your coolant reservoir. Is it low? If so, you likely have a leak somewhere. Never open a hot radiator cap! Let the engine cool completely before checking the coolant level or anything else under the hood. If it's low, adding coolant is a temporary fix; you need to find the leak.
* Radiator Fan: With the engine running, is the radiator fan working? You should hear it turn on as the engine warms up. If not, the fan, its motor, or the fan's control system (electrical or thermostatically controlled) could be faulty.
* Thermostat: A stuck closed thermostat prevents coolant from circulating, leading to overheating. This is a common culprit. You'll need to replace this if it's faulty.
* Obvious Leaks: Carefully inspect all hoses, the radiator itself, and the water pump for any visible leaks. Look for wet spots, stains, or dripping coolant.
2. Less Obvious, but Still Relatively Simple Checks:
* Coolant Circulation: If you can safely and carefully feel the upper and lower radiator hoses when the engine is running (after it's warmed up but *not* boiling*), the upper hose should be hot and the lower hose should also be hot (though maybe a little less so). If the lower hose is cold, coolant isn't circulating properly. This points to a thermostat or water pump problem.
* Head Gasket: A blown head gasket is a more serious issue. This allows coolant to mix with engine oil (milky oil) or enter the combustion chamber (white smoke from the exhaust). Check your oil dipstick for milky residue. White smoke, especially when the engine is cold, is another strong indicator.
* Blocked Radiator: A clogged radiator restricts coolant flow. This requires a more involved cleaning or replacement.
3. More Involved Issues (Likely require a mechanic):
* Water Pump: A failing water pump can't effectively circulate coolant.
* Faulty Radiator Cap: A faulty cap might not maintain proper pressure in the cooling system.
* Clogged Heater Core: Less common, but a blocked heater core can contribute to overheating.
What to do next:
1. Safety First: If your engine is overheating, pull over immediately and turn off the engine. Continuing to drive could cause serious damage.
2. Start with the easy checks: Coolant level, radiator fan, obvious leaks.
3. If you're not comfortable working on your car: Take it to a mechanic. Overheating can lead to expensive engine damage. Clearly explain the symptoms to them.
4. Document your findings: Keep notes on what you've checked and the results. This helps the mechanic diagnose the problem efficiently.
A 1998 Cavalier is an older car, so some parts might be worn out. Addressing the problem promptly is key to preventing catastrophic engine failure.
