Possible Causes:
* Thermostat Stuck Closed: This is a common culprit. A stuck thermostat prevents coolant from circulating properly, leading to overheating. It's relatively inexpensive and easy to replace.
* Air Pockets in the Cooling System: Air trapped in the system can impede coolant flow. Proper bleeding of the system is crucial after any coolant work (including adding coolant). There are specific procedures for bleeding a Corvette's cooling system – consult your owner's manual or a repair guide.
* Failing Water Pump (despite being new): While you mention a new water pump, it's possible it's faulty or not installed correctly. Verify impeller rotation and proper installation.
* Radiator Cap Issues: A faulty radiator cap can prevent proper pressure buildup in the system, leading to inefficient cooling. Replace it as a preventative measure.
* Faulty Fan Clutch (if applicable): Some Corvette models use a viscous fan clutch. If this clutch is failing, the fan may not be spinning at sufficient speed.
* Head Gasket Failure: This is a more serious issue that allows combustion gases to enter the cooling system. Symptoms can include white smoke from the exhaust, milky oil, and pressure in the cooling system. This requires a significant repair.
* Clogged Radiator: While you say the radiator is in excellent shape, internal clogging is possible, reducing coolant flow.
* Incorrect Coolant Mixture: Ensure you're using the correct mix of coolant and distilled water. Using too much or too little coolant can negatively affect the boiling point.
Troubleshooting Steps:
1. Check the Thermostat: The easiest and cheapest thing to check first. Replace it if it's stuck closed.
2. Bleed the Cooling System: Carefully follow the procedure to remove air pockets.
3. Check Radiator Cap: Replace it, as they are relatively inexpensive and a common point of failure.
4. Verify Fan Operation: Make sure both fans are coming on at the correct temperatures. Consider a temperature gun to measure fan operation.
5. Inspect for Leaks: Carefully check all hoses, clamps, and the radiator for any leaks.
6. Pressure Test the Cooling System: This will help identify any leaks that aren't easily visible.
7. Check for White Smoke/Milky Oil: These are indicators of a potential head gasket problem.
Adding 48 oz of coolant: This is a temporary fix. The underlying problem needs to be addressed to prevent engine damage. Continuously adding coolant without fixing the root cause is a sign of a serious leak or other problem.
Recommendation: Don't drive the car until you've diagnosed and fixed the overheating problem. Continued driving at 230°F will severely damage the engine. If you're not comfortable performing these checks yourself, take it to a qualified mechanic. A proper diagnosis is essential to prevent further damage and costly repairs.
