Loss of Coolant (LSY)
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
Special Tools
GE-42220 Universal 12V Leak Detection Lamp
Equivalent regional tools:Special Tools .
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The cooling system is losing coolant either internally or externally. | |||
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - Engine Cooling |
| 2 | Repair any present DTCs. Diagnostic System Check - Vehicle Is the action complete? |
Go to Step 3 | - |
| 3 | Inspect the coolant level. Is the coolant at the proper level? |
Go to Step 5 | Go to Step 4 |
| 4 | Fill the cooling system to the proper level. Cooling System Draining and Filling (LSY GE 47716)Cooling System Draining and Filling (LSY Static Fill)Cooling System Draining and Filling (LSY with V03 Static Fill)Cooling System Draining and Filling (L3B Static Fill)Cooling System Draining and Filling (L3B GE 47716)Cooling System Draining and Filling (LSY with V03 GE 47716)Cooling System Draining and Filling (LF4 Static Fill)Cooling System Draining and Filling (LF4 GE 47716) Is the action complete? |
Go to Step 5 | - |
| 5 | If the engine is suspected to have a coolant leak into a cylinder, the coolant can hydraulically lock the engine. Does the engine crankshaft rotate? |
Go to Step 6 | Go to Step 27 |
| 6 | Engine overheating can cause a loss of coolant. Is the engine overheating? |
Go to Step 28 | Go to Step 7 |
| 7 | Extended operation with a low coolant level can cause engine internal component failure. Is the engine knocking? |
Go to Step 30 | Go to Step 8 |
| 8 |
|
Go to Step 9 | Go to Step 10 |
| 9 |
|
Go to Step 29 | Go to Step 10 |
| 10 |
WARNING:
With the engine idling, inspect the radiator surge tank.Does the radiator surge tank discharge coolant while the engine is idling? |
Go to Step 14 | Go to Step 11 |
| 11 | Visually inspect the coolant hoses, pipes and hose clamps at the following locations:
Are any of the coolant hoses, clamps or pipes leaking? |
Go to Step 21 | Go to Step 12 |
| 12 | Visually inspect the following components:
Are any of the listed components leaking? |
Go to Step 21 | Go to Step 13 |
| 13 |
|
Go to Step 21 | Go to Step 14 |
| 14 | Pressure test the radiator surge tank cap. Radiator Surge Tank Cap Testing Does the coolant radiator surge tank cap hold pressure? |
Go to Step 15 | Go to Step 22 |
| 15 | Inspect for the following conditions:
Is coolant present? |
Go to Step 23 | Go to Step 16 |
| 16 |
|
Go to Step 21 | Go to Step 17 |
| 17 | Use GE-42220
Universal 12V Leak Detection Lamp to inspect for the following conditions:
Is coolant system tracer dye present? |
Go to Step 23 | Go to Step 18 |
| 18 | Inspect the underside of the engine oil fill cap for a gray/white milky substance. Is there a milky substance on under the oil fill cap? |
Go to Step 19 | Go to Step 20 |
| 19 | Inspect the engine oil fluid level indicator for a gray/white milky substance. Is there a milky substance on the engine oil fluid level indicator? |
Go to Step 29 | Go to Step 20 |
| 20 | Inspect the automatic transmission oil fluid level indicator, if equipped, for a gray/white milky substance. Is there a milky substance on the automatic transmission fluid level indicator? |
Go to Step 24 | Go to Step 31 |
| 21 | Repair or replace the leaking component. Is the repair complete? |
Go to Step 31 | - |
| 22 | Replace the radiator surge tank cap. Is the repair complete? |
Go to Step 31 | - |
| 23 | Replace the heater core. Heater Core Replacement Is the repair complete? |
Go to Step 31 | - |
| 24 |
|
Go to Step 25 | Go to Step 26 |
| 25 |
|
Go to Step 31 | - |
| 26 | Install the cooler lines to the radiator. Is the action complete? |
Go to Step 31 | - |
| 27 | Repair the engine no crank condition. Engine Will Not Crank - Crankshaft Will Not Rotate Is the repair complete? |
Go to Step 31 | - |
| 28 | Repair the engine overheating condition. Engine Overheating (LSY) Engine Overheating (LF4) Is the repair complete? |
Go to Step 31 | - |
| 29 | Repair the engine internal coolant leak. Is the repair complete? |
Go to Step 31 | - |
| 30 | Repair the engine knock. Lower Engine Noise, Regardless of Engine Speed Is the repair complete? |
Go to Step 31 | - |
| 31 | Operate the system in order to verify the repair. Did you find and correct the condition? |
System OK | Go to Step 2 |