Engine Cooling: Diagnosis Ford Econoline E350 Super Duty

Inspection and Verification

1. Verify the customer's concern by operating the engine to duplicate the condition.
2. Inspect to determine if any of the following mechanical or electrical concerns apply. ENGINE COOLING VISUAL INSPECTION CHART Mechanical Electrical Leaks Damaged hoses Loose/damaged hose clamps Damaged head gaskets Damaged intake manifold gasket Damaged coolant pump Damaged radiator Damaged degas bottle Damaged heater core Damaged fan/fan clutch Damaged engine coolant temperature sensor Damaged wiring
3. If the inspection reveals an obvious concern that can be readily identified, repair as necessary.
4. Inspect the coolant condition. Inspect the coolant color: If Motorcraft Premium Gold Engine Coolant VC-7-A (yellow color) or equivalent meeting Ford specification WSS-M97B51-A1 has a clear or pale yellow color, this indicates higher water content than required. Dark brown could indicate unauthorized Stopleak may have been used. Use Cooling System Stop Leak Pellets VC-6 or equivalent meeting Ford specification WSS-M99B37-B6. A light or reddish brown color indicates that rust may be present in the cooling system. Flush the system and refill with the correct mixture of distilled water and Motorcraft Premium Gold Engine Coolant. An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system. For additional information on engine diagnosis, refer to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-231364) . A milky brown color may indicate that either engine oil or transmission fluid is entering the cooling system. If transmission fluid is suspected, the cause may be a leaky radiator. Pressure test the cooling system. For additional information, refer to «COMPONENT TESTS»(ref-231368-S40460408182006050800000) in this section. If engine oil is suspected, the cause of the leak may be internal to the engine. For additional information on engine diagnosis, refer to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-231364) . If transmission fluid is contaminated with engine coolant, the cause may be a leaky radiator. Pressure test the system. For additional information, refer to the «COMPONENT TESTS»(ref-231368-S40460408182006050800000) . If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the special tool. The freezing point should be in the range of -50°F to -10°F. If the vehicle is driven in cold climates (lower than -34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Maximum coolant concentration is 60/40. Minimum coolant concentration is 40/60. Adjust coolant range and level if necessary: If coolant is low, add specified coolant mixture only. If the engine coolant tests too weak, add straight engine coolant until the readings are within acceptable levels. If the engine coolant tests strong, remove some of the engine coolant and add distilled water until the readings are within acceptable levels.
5. If the concern remains after the inspection, determine the symptom(s). GO to «SYMPTOM CHART»(ref-231368-S11822770072006050800000) .

Symptom Chart

ENGINE COOLING SYMPTOM CHART

PINPOINT TEST A: LOSS OF COOLANT

1. A1 CHECK THE ENGINE COOLANT LEVEL WARNING: To avoid personal injury, do not unscrew the coolant pressure relief cap while the engine is operating or hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. NOTE: Allow the engine to cool before checking the engine coolant level. Key in OFF position. Visually check the engine coolant level at the degas bottle. Is the engine coolant level within specification? Yes : GO to A2. No : REFILL the engine coolant as necessary. GO to A2.
2. A2 CHECK THE PRESSURE RELIEF CAP WARNING: To avoid personal injury, do not unscrew the coolant pressure relief cap while the engine is operating or hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. NOTE: Allow the engine to cool before checking the engine coolant level. Carry out the pressure relief cap test. Refer to «PRESSURE TEST»(ref-231368-S02093126362006050800000) . Is pressure relief cap OK? Yes : GO to A3. No : INSTALL a new pressure relief cap. TEST the system for normal operation.
3. A3 CHECK THE ENGINE COOLANT FOR INTERNAL LEAK WARNING: To avoid personal injury, do not unscrew the coolant pressure relief cap while the engine is operating or hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Key in OFF position. Inspect the engine coolant in degas bottle for signs of transmission fluid or engine oil. Is oil or transmission fluid evident in coolant? Yes : If engine oil is evident, GO to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-231364) . If transmission fluid is evident, INSTALL a new radiator. No : GO to A4.
4. A4 CHECK THE ENGINE AND THE TRANSMISSION FOR COOLANT Remove the oil level dipsticks from the engine and the transmission. Is coolant evident in oil or transmission fluid? Yes : If coolant is in engine, GO to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-231364) . If coolant is in transmission, INSTALL a new radiator. No : GO to A5.
5. A5 PRESSURE TEST THE ENGINE COOLING SYSTEM Pressure test the engine cooling system. Refer to the «COMPONENT TESTS»(ref-231368-S40460408182006050800000) . Does the engine cooling system leak? Yes : REPAIR or INSTALL new components. TEST the system for normal operation. No : The cooling system is operational. GO to «SYMPTOM CHART»(ref-231368-S11822770072006050800000) .

PINPOINT TEST B: THE ENGINE OVERHEATS

1. B1 CHECK THE ENGINE COOLANT LEVEL WARNING: Never remove the pressure relief cap while the engine is operating or when the cooling system is hot. Failure to follow these instructions can result in damage to the cooling system or engine or personal injury. To avoid having scalding hot coolant or steam blow out of the degas bottle when removing the pressure relief cap. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly. Step back while the pressure is released from the cooling system. When you are sure all the pressure has been released, turn and remove the pressure relief cap (still with a cloth). NOTE: If the engine is hot, allow the engine to cool before proceeding. Key in OFF position. Make sure the engine is cool. Wrap a thick cloth around the coolant pressure relief cap on the degas bottle. Slowly turn the cap counterclockwise (left) until the pressure begins to release. Step back while the pressure releases. When you are sure all the pressure has been released, use the cloth to turn and remove the cap. Check the engine coolant level at the degas bottle. Is the engine coolant OK? Yes : GO to B2. No : REFILL the engine coolant at the degas bottle. GO to «PINPOINT TEST A»(ref-231368-S22721959572006050800000) .
2. B2 CHECK THE COOLANT CONDITION Check the coolant for rust, dirt or contamination. Is the coolant condition OK? Yes : GO to B3. No : FLUSH the engine cooling system; REFER to «COOLING SYSTEM FLUSHING»(ref-231368-S16155805132006050800000) . TEST the system for normal operation.
3. B3 CHECK FOR AN AIRFLOW OBSTRUCTION Inspect the A/C condenser core and radiator for obstructions such as leaves or dirt. Is there an obstruction? Yes : REMOVE the obstruction. CLEAN the A/C condenser core and radiator. TEST the system for normal operation. No : GO to B5 .
4. B4 CHECK THE THERMOSTAT OPERATION Start the engine and allow the engine to run for ten minutes. Feel the inlet and outlet heater hoses and the underside of the upper radiator hose. Are the upper radiator hose and the heater water hoses cold? Yes : INSTALL a new thermostat. TEST the system for normal operation. No : GO to B5.
5. B5 CHECK THE COOLING FAN OPERATION Key in OFF position. Carry out the cooling fan component tests. Refer to «FAN CLUTCH TEST»(ref-231368-S11673858452006050800000) . For 6.0L diesel, see «INTRODUCTION -- 6.0L DIESEL»(ref-232980) article. Is the cooling fan operation OK? Yes : GO to «ENGINE SYSTEM-GENERAL INFORMATION»(ref-231364) or Diagnosis and Testing of the engine. No : INSTALL a new fan component determined to be faulty. TEST the system for normal operation.

PINPOINT TEST C: THE ENGINE DOES NOT REACH NORMAL OPERATING TEMPERATURE

1. C1 CHECK THE ENGINE TEMPERATURE Start the engine and allow the engine to idle for ten minutes. Key in OFF position. Feel the inlet and heater hoses and the underside of the upper radiator hose. Are the upper radiator hose and the heater hoses cold? Yes : INSTALL a new thermostat. TEST the system for normal operation. No : GO to «INSTRUMENT CLUSTER»(ref-231355) for diagnosis and testing of the engine coolant temperature gauge.

Pressure Test

1. Turn the engine OFF.
2. Check the engine coolant level. Refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-231368-S10128955572006050800000) .
3. Connect Radiator Heater Core Pressure Tester to the degas bottle nipple and overflow hose. Install a pressure test pump to the quick-connect fitting of the test adapter.
4. Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.
5. If the pressure relief cap does not hold pressure, remove and wash the pressure relief cap in clean water to dislodge all foreign particles from the gaskets. Check the sealing surface in the filler neck.
6. If 89 kPa (13 psi) cannot be reached, install a new pressure relief cap. If more than 124 kPa (18 psi) shows on gauge, install a new pressure relief cap.
7. Pressurize the engine cooling system as described in Step 4 (using a pressure relief cap that operates within the specified upper and lower pressure limits). Observe the gauge reading for approximately two minutes; refer to «GENERAL SPECIFICATIONS»(ref-231368-S00137823082006050800000) . Pressure should not drop during this time.
8. Release the system pressure by loosening the pressure relief cap. Check the engine coolant level and replenish, if necessary, with the correct engine coolant mixture; refer to «COOLING SYSTEM DRAINING, FILLING AND BLEEDING»(ref-231368-S10128955572006050800000) .

Thermostat, Electrical Test-4.6L, 5.4L and 6.8L

Note. The electrical thermostat test is most accurate if carried out indoors at less than 37.8°C (100°F) ambient air. This test may be carried out with the hood open or closed and with the engine warm or cold.

1. Check the engine coolant level. Fill as needed.
2. With the ignition OFF, voltage values (0-5 V) may now be monitored while the cylinder head temperature (CHT) sensor retains its connection to the wiring harness. A scan tool is used to monitor the CHT voltage.
3. Place the automatic transmission in PARK (P) or the manual transmission in NEUTRAL (N) and engage the parking brake.
4. Start the engine and allow the engine to idle throughout this test. Allow the engine to run for two minutes, then record the CHT voltage. Record the CHT voltage every 60 seconds. When the CHT voltage trend changes direction or only changes slightly (0.03 volt or less) from the previous reading, record this as the thermostat opening voltage. Use the voltage and corresponding coolant temperature chart listed below. VOLTAGE AND COOLANT TEMPERATURE CHART Coolant Temperature °C (°F) CHT (Volts) 22 (71) 3.00 43 (109) 2.01 71 (159) 1.01 82 (180) 0.75 92 (197) 0.58 97 (206) 0.50 105 (221) 0.40
5. If the coolant thermostat opening voltage is greater than 0.58 volt and less than 92°C (197°F), install a new coolant thermostat.
6. If the coolant thermostat opening voltage is less than 0.58 volt and greater than 92°C (197°F), the coolant thermostat is good and a new coolant thermostat should not be installed. GO to «SYMPTOM CHART»(ref-231368-S11822770072006050800000) for further instructions.

Thermostat - Mechanical Test

1. Remove the thermostat.
2. Check the thermostat for seating. Hold the thermostat up to a lighted background. Leakage of light around the thermostat valve at room temperature indicates that a new thermostat should be installed. Some thermostats have a small leakage notch at one location on the perimeter of the thermostat valve, which is considered normal.
3. Immerse the thermostat in a boiling antifreeze and water mixture.
4. See the «GENERAL SPECIFICATIONS CHART»(ref-231368-S00137823082006050800000) for thermostat opening temperatures.

Radiator Leak Test, Removed From the Vehicle

Note. Always install plugs in the oil cooler fittings before leak-testing or cleaning any radiator.

Note. Clean the radiator before leak-testing to avoid contamination of tank.

1. Leak-test the radiator in clean water with 138 kPa (20 psi) air pressure.
2. If a stream of air bubbles is observed coming from the radiator, note the location and install a new radiator.

Fan Clutch Test

Note. The following test does not apply to the 6.0L diesel. For the 6.0L diesel, see INTRODUCTION -- 6.0L DIESEL article.

1. Spin the fan blade by hand. A light resistance should be felt. If there is no resistance or very high resistance, the minimum and maximum fan speeds must be checked as follows

Fan Clutch Test - Minimum Speed Requirement

1. Use a suitable marker to mark the water pump pulley, one of the fan blade retaining bolts and the crankshaft pulley.
2. Connect a tachometer to the engine.
3. Install a throttle adjusting tool.
4. Connect the Digital Photoelectric Tachometer.
5. Start the engine and run it at approximately 1,500 rpm until the normal operating temperature has been achieved.
6. Adjust the engine speed to 2,300 rpm.
7. Operate the strobe light at 3,000 rpm and aim it at the coolant pump pulley. Adjust the engine speed until the light flash and the coolant pump pulley mark are synchronized.
8. Aim the strobe light at the fan blade bolts. Adjust the strobe light until the light flash is synchronized with the marked fan blade bolt (the fan blade appears to stand still).
9. The fan blade speed must not be greater than 1,500 rpm at 3,000 coolant pump rpm.
10. Turn the engine off.
11. If the fan blade speed was greater than 1,500 rpm, install a new fan clutch.

Fan Clutch Test - Maximum Speed Requirement

1. Carry out Steps 1 through 5 of the Fan Clutch Test - Minimum Speed Requirement.
2. Block off areas on each side of the radiator in the engine compartment and the front of the radiator grille. This will raise the temperature of the air striking the fan clutch and should cause the fan blade to operate at maximum speed.
3. Place the climate control function selector switch in the MAX A/C position and the blower motor switch in the HI position.
4. Adjust the strobe to 3,000 rpm.
5. Start the engine and adjust the engine speed until the strobe light flash and the water pump pulley mark are synchronized.
6. Aim the strobe light at the fan blade retaining bolts. Adjust the strobe light until the light flash is synchronized with the marked fan blade bolt (the fan blade appears to stand still).
7. If the fan blade speed is less than 2,300 rpm, install a new fan clutch.