LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1451 (Engine Cooling System) >> Diagnostic Information and Procedures >> Loss of Coolant

Loss of Coolant

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Loss of Coolant

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. Refer to Diagnostic Trouble Code (DTC) List  .
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. Refer to Draining and Filling Cooling System (LL8)  or Draining and Filling Cooling System (LM4)  .
Is the action complete?		 Go to Step 5  -
5 If the engine is suspected to have a coolant leak into the cylinder, the coolant can hydraulically lock the cylinder.
Does the engine crankshaft rotate?		 Go to Step 6  Go to Step 30 
6 Engine overheating can cause a loss of coolant.
Is the engine overheating?		 Go to Step 31  Go to Step 7 
7 Extended engine operation with a low coolant level can cause engine internal component failure.
Is the engine knocking?		 Go to Step 33  Go to Step 8 
8
  1. Idle the engine at normal operating temperature.
  2. Inspect for heavy white smoke coming out of the exhaust pipe.
Is a heavy white smoke present from the exhaust pipe?		 Go to Step 9  Go to Step 10 
9
  • Coolant in the exhaust system creates a distinctive, burning coolant odor in the exhaust.
  • Condensation in the exhaust system can cause an odorless white smoke during engine warm up.
Does the white smoke have a burning coolant type odor?		 Go to Step 32  Go to Step 10 
10 With the engine idling, inspect the coolant recovery system.
Does the coolant recovery system discharge coolant while the engine is idling?		 Go to Step 15  Go to Step 11 
11 Visually inspect the hoses, pipes and hose clamps at the following locations:
  • Auxiliary heater
  • Coolant bypass
  • Coolant reservoir
  • Heater
  • Radiator

Are any of the hoses, clamps or pipes leaking?		 Go to Step 21  Go to Step 12 
12 Visually inspect the following components:
  • Block heater
  • Coolant pressure cap
  • Coolant reservoir
  • Core plugs
  • Cylinder head gaskets
  • Engine block
  • Intake manifold
  • Radiator
  • Thermostat
  • Water pump

Are any of the listed components leaking?		 Go to Step 21  Go to Step 13 
13
  1. Pressure test the cooling system. Refer to Cooling System Leak Testing  .
  2. Visually inspect the components listed in steps 11 and 12 again.
Are any leaks present?		 Go to Step 21  Go to Step 14 
14 Pressure test the coolant pressure cap. Refer to Pressure Cap Testing  .
Does the coolant pressure cap hold pressure?		 Go to Step 16  Go to Step 22 
15 Pressure test the coolant pressure cap. Refer to Pressure Cap Testing  .
Does the coolant pressure cap hold pressure?		 Go to Step 34  Go to Step 22 
16 Inspect for the following conditions:
  • A coolant smell inside of the vehicle.
  • Coolant in the HVAC module drain tube.
  • Coolant on the vehicles floor covering under the HVAC module.

Is coolant present?		 Go to Step 23  Go to Step 17 
17 If equipped with auxiliary heating, inspect for the following:
  • A coolant smell inside of the vehicle.
  • Coolant in the auxiliary HVAC module drain tube.
  • Coolant on the floor covering near the auxiliary HVAC module.

Is coolant present?		 Go to Step 24  Go to Step 18 
18 Inspect the underside of the oil fill cap for a gray/white milky substance.
Is there a milky substance 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 fluid level indicator?		 Go to Step 25  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 27  Go to Step 35 
21 Repair or replace the leaking component. Refer to the appropriate repair.
Is the repair complete?		 Go to Step 35  -
22 Replace the coolant pressure cap.
Is the repair complete?		 Go to Step 35  -
23 Replace the heater core. Refer to Heater Core Replacement in Heating, Ventilation and Air Conditioning.
Is the repair complete?		 Go to Step 35  -
24 Replace the auxiliary heater core. Refer to Heater Core Replacement - Auxiliary in Heating, Ventilation and Air Conditioning.
Is the repair complete?		 Go to Step 35  -
25
  1. Remove the engine oil cooler lines from the radiator, if equipped.
  2. Pressure test the cooling system. Refer to Cooling System Leak Testing  .
  3. Inspect the engine oil cooler for coolant.
Is coolant present in the engine oil cooler?		 Go to Step 26  Go to Step 29 
26
  1. Replace the radiator. Refer to Radiator Replacement (LL8)  or Radiator Replacement (LM4)  .
  2. Service the engine oil and filter. Refer to Engine Oil and Oil Filter Replacement in Engine Mechanical - 4.2L or Engine Oil and Oil Filter Replacement in Engine Mechanical - 4.8L, 5.3L and 6.0L.
Is the repair complete?		 Go to Step 35  -
27
  1. Remove the transmission oil cooler lines from the radiator.
  2. Pressure test the cooling system. Refer to Cooling System Leak Testing  .
  3. Inspect the transmission oil cooler for coolant.
Is coolant present in the transmission oil cooler?		 Go to Step 28  Go to Step 29 
28
  1. Replace the radiator. Refer to Radiator Replacement (LL8)  or Radiator Replacement (LM4)  .
  2. Service the automatic transmission. Refer to Automatic Transmission Fluid/Filter Replacement in Automatic Transmission - 4L60-E/4L65-E.
Is the repair complete?		 Go to Step 35  -
29 Install the cooler lines to the radiator.
Is the repair complete?		 Go to Step 35  -
30 Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 4.2L or Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical - 4.8L, 5.3L and 6.0L.
Is the repair complete?		 Go to Step 35  -
31 Repair the engine overheating condition. Refer to Engine Overheating  .
Is the repair complete?		 Go to Step 35  -
32 Repair the engine internal coolant leak. Refer to Coolant in Combustion Chamber in Engine Mechanical - 4.2L or Coolant in Combustion Chamber in Engine Mechanical - 4.8L, 5.3L and 6.0L.
Is the repair complete?		 Go to Step 35  -
33 Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 4.2L or Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical - 4.8L, 5.3L and 6.0L.
Is the repair complete?		 Go to Step 35  -
34 Repair the combustion pressure in the cooling system problem. Refer to Cylinder Leakage Test in Engine Mechanical - 4.2L or Cylinder Leakage Test in Engine Mechanical - 4.8L, 5.3L and 6.0L.
Is the repair complete?		 Go to Step 35  -
35 Operate the system in order to verify the repair.
Did you find and correct the condition?		 System OK Go to Step 2 
scientia non olet · About LEMON Manuals