TEMPERATURE GAUGE READS HIGH OR ENGINE COOLANT WARNING LAMP ILLUMINATES. COOLANT MAY OR MAY NOT BE LOST FROM SYSTEM.
1. Trailer being towed, a steep hill being climbed, vehicle being operated in slow moving traffic, or engine idling during high ambient (outside) temperatures with air conditioning on. High altitudes could also cause these conditions.
1. This may be a temporary condition and repair is not necessary. Turn off the air conditioning and drive the vehicle without any of the previous conditions. Observe the temperature gauge. The gauge should return to the normal range. If the gauge does not return to the normal range, determine the cause of the overheating and repair.
2. Inoperative temperature gauge.
2. Check gauge operation (Refer to 08 - Electrical/8J - Instrument Cluster - Operation) .
3. Is temperature warning lamp (if equipped) illuminating unnecessarily?
3. Check warning lamp operation (Refer to 08 - Electrical/8J - Instrument Cluster/INDICATORS, Instrument Cluster - Operation) .
4. Coolant low in recovery/reserve bottle and radiator?
4. Check for coolant leaks and repair as necessary.
5. Pressure cap not installed tightly. If cap is loose, boiling point of coolant will be lowered. Also refer to the following step 6.
5. Tighten cap.
6. Poor seals at pressure cap.
6. (a) Check condition of cap and cap seals (Refer to 07 - Cooling/Engine/CAP, Radiator - Diagnosis and Testing) . Replace cap if necessary.
(b) Check condition of filler neck. If neck is warped or damaged, replace neck.
7. Coolant level low in radiator, but not in coolant recovery/reserve bottle. This indicates the radiator is not drawing coolant from the coolant recovery/reserve bottle as the engine cools. As the engine cools, a vacuum is formed inside the cooling system. If the pressure cap seals are defective, or the cooling system has a leak, a vacuum cannot be formed.
7. (a) Check condition of pressure cap and cap seals. Replace cap if necessary.
(b) Check condition of filler neck. Replace if damaged.
(c) Check condition of hose from filler neck to coolant container. It should be tight at both ends without any kinks or tears. Replace hose as necessary.
(d) Check coolant recovery/reserve bottle and hose for blockage. Repair as necessary.
8. Freeze point of coolant not correct. Mixture ratio may be too rich.
8. Check coolant concentration (Refer to 07 - Cooling/Engine/COOLANT - Diagnosis and Testing) . Adjust glycol-to-water ratio as required.
9. Coolant not flowing through system.
9. Check for coolant flow at filler neck with some coolant removed, engine warm, and thermostat open. Coolant should be observed flowing through filler neck. If flow is not observed, determine reason for lack of flow and repair as necessary.
10. Radiator air seals missing or improperly installed.
10. Inspect air seals. Correct as necessary.
11. Radiator or A/C condenser fins are dirty or clogged.
11. Clean obstruction from fins.
12. Radiator core is plugged or corroded.
12. Replace or clean radiator.
13. Fuel or ignition system problems.
13. Refer to the appropriate Powertrain Diagnostic Procedure manual.
14. Dragging Brakes.
14. Inspect brake system and repair as necessary (Refer to 05 - Brakes - Diagnosis and Testing) .
15. Bug screen or other aftermarket accessory is being used causing reduced air flow.
15. Remove bug screen or accessory.
16. Thermostat partially or completely closed.
16. Check thermostat operation and replace as necessary (Refer to 07 - Cooling/Engine/THERMOSTAT - Removal) .
17. Cooling fan not operating properly.
17. Check electric fan operation and repair as necessary.
18. Cylinder head gasket leaking.
18. Check cylinder head gasket for leaks (Refer to 07 - Cooling - Diagnosis and Testing) .
19. Heater core leaking.
19. Check heater core for leaks.
This is a generic diagnosis tree and some of it does not apply even though it is from a Dart FSM. There is a special tool for filling the system to purge air. It sounds like you may have an air bubble or a leak. Have you replaced the coolant recently or have you done anything with the cooling system? Have you done a pressure test?