Here are some likely culprits:
* Crankshaft Position Sensor (CKP Sensor): This sensor is crucial for the engine's timing. Heat can cause them to fail intermittently. When hot, the sensor might be giving inaccurate signals, causing the engine to stall. This is a common problem that often doesn't trigger a CEL.
* Camshaft Position Sensor (CMP Sensor): Similar to the CKP sensor, a failing CMP sensor can also lead to stalling, especially when the engine is hot. Again, it may not always throw a CEL.
* Ignition Control Module (ICM): The ICM controls the ignition system. Heat can damage it, causing it to malfunction and shut off the engine when hot.
* Coolant Temperature Sensor (CTS): While a faulty CTS might affect performance, it's less likely to directly cause the engine to shut off. However, an incorrect reading could contribute to other problems.
* Fuel Pump Relay: While less likely, a heat-sensitive relay could also be causing the problem. It's possible the relay is failing when the engine bay gets hot.
* Wiring Issues: Look for any damaged or corroded wiring, particularly around the sensors and ignition system components. Heat can exacerbate existing wiring problems.
Troubleshooting Steps:
1. Check for obvious issues: Inspect the obvious things first:
* Low coolant: Is your coolant level low? A low coolant level can cause overheating, leading to stalling.
* Loose connections: Check all connections to sensors and ignition components.
* Visual Inspection: Look for any obvious signs of damage to wires, connectors, or components.
2. Test the Coolant Temperature Sensor (CTS): A multimeter can be used to test the resistance of the CTS at different temperatures. Compare the readings to the specifications in your repair manual.
3. Consider the CKP and CMP Sensors: These are the most likely culprits given the symptoms. Testing these requires a multimeter and a bit more technical knowledge. You may need to consult a repair manual for specific testing procedures. Replacing them is often the most straightforward solution if faulty.
4. Inspect the Ignition System: Check the ignition coil, spark plugs, and wires for any cracks or damage.
5. Fuel Pump Pressure Test: This is more involved and may require specialized tools but can help determine if the fuel pump is functioning correctly under heat stress.
6. Professional Diagnosis: If you're not comfortable performing these tests yourself, take your car to a qualified mechanic. They can perform a proper diagnosis and pinpoint the exact cause of the problem. They might use a scan tool to look for any hidden codes even if the CEL isn't on.
Since the CEL isn't illuminating, it makes this more challenging. Start with the easier checks (coolant, connections, visual inspection) and then move on to testing sensors if necessary. Remember safety first – work on a cool engine and be aware of hot surfaces.
