INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a small amount of engine oil. If coolant is present in the pan, it will drain first because it is heavier than oil. An alternative method is to operate engine for a short period to churn the oil. After this is done, remove engine dipstick and inspect for water globules. Also inspect the transmission dipstick for water globules and the transmission fluid cooler for leakage.
| WARNING | With radiator pressure tester tool installed on radiator, do not allow pressure to exceed 145 kPa (21 psi). Pressure will build up quickly if a combustion leak is present. To release pressure, rock tester from side to side. When removing tester, do not turn tester more than 1/2 turn if system is under pressure. |
Operate the engine without the pressure cap on the radiator until the thermostat opens. Attach a Pressure Tester to filler neck. If pressure builds up quickly it indicates a combustion leak exists. This is usually the result of a cylinder head gasket leak or crack in engine. Repair as necessary.
If there is not an immediate pressure increase, pump the Pressure Tester. Do this until indicated pressure is within system range of 124.1 kPa (18 psi). Fluctuation of gauge pointer indicates compression or combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic converter, do not remove spark plug cables or short out cylinders to isolate compression leak.
If the needle on the dial of pressure tester does not fluctuate, race engine a few times to check for an abnormal amount of coolant or steam. This would be emitting from exhaust pipe. Coolant or steam from exhaust pipe may indicate a faulty cylinder head gasket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into cooling system is provided by a commercially available Block Leak Check tool. Follow manufacturers instructions when using this product.
COMBUSTION LEAKAGE TEST - WITHOUT PRESSURE TESTER
DO NOT WASTE reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.
| WARNING | Do not remove cylinder block drain plugs or loosen radiator draincock with system hot and under pressure. Serious burns from coolant can occur. |
Drain sufficient coolant to allow thermostat removal. See Cooling/Engine/THERMOSTAT - Removal for 3.5L engine, also see Cooling/Engine/THERMOSTAT - Removal for 5.7L engine. Remove accessory drive belt. See Cooling/Accessory Drive/BELT, Serpentine - Removal .
Add coolant to radiator to bring level to within 6.3 mm (1/4 in) of the top of the thermostat housing.
| CAUTION | Avoid overheating. Do not operate engine for an excessive period of time. Open draincock immediately after test to eliminate boil over. |
Start engine and accelerate rapidly three times, to approximately 3000 RPM while observing coolant. If internal engine combustion gases are leaking into cooling system, bubbles will appear in coolant. If bubbles do not appear, internal combustion gas leakage is not present.
Establish what driving conditions caused the complaint. Abnormal loads on the cooling system such as the following may be the cause
- Prolonged idle
- Very high ambient temperature
- Slight tail wind at idle
- Slow traffic
- Traffic jams
- High speed or steep grades
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are most noticeable at idle. Before replacing a belt to resolve a noise condition, inspect all of the accessory drive pulleys for alignment, glazing, or excessive end play.
| CONDITION | POSSIBLE CAUSES | CORRECTION |
|---|---|---|
| RIB CHUNKING (One or more ribs has separated from belt body) | 1. Foreign objects imbedded in pulley grooves. | 1. Remove foreign objects from pulley grooves. Replace belt. |
| 2. Installation damage | 2. Replace belt | |
| RIB OR BELT WEAR | 1. Pulley misaligned | 1. Align pulley(s) |
| 2. Abrasive environment | 2. Clean pulley(s). Replace belt if necessary | |
| 3. Rusted pulley(s) | 3. Clean rust from pulley(s) | |
| 4. Sharp or jagged pulley groove tips | 4. Replace pulley. Inspect belt. | |
| 5. Belt rubber deteriorated | 5. Replace belt | |
| BELT SLIPS | 1. Belt slipping because of insufficient tension | 1. Inspect/Replace tensioner if necessary |
| 2. Belt or pulley exposed to substance that has reduced friction (belt dressing, oil, ethylene glycol) | 2. Replace belt and clean pulleys | |
| 3. Driven component bearing failure (seizure) | 3. Replace faulty component or bearing | |
| 4. Belt glazed or hardened from heat and excessive slippage | 4. Replace belt. | |
| LONGITUDINAL BELT CRACKING | 1. Belt has mis-tracked from pulley groove | 1. Replace belt |
| 2. Pulley groove tip has worn away rubber to tensile member | 2. Replace belt | |
| "GROOVE JUMPING" (Belt does not maintain correct position on pulley) | 1. Incorrect belt tension | 1. Inspect/Replace tensioner if necessary |
| 2. Pulley(s) not within design tolerance | 2. Replace pulley(s) | |
| 3. Foreign object(s) in grooves | 3. Remove foreign objects from grooves | |
| 4. Pulley misalignment | 4. Align component | |
| 5. Belt cord line is broken | 5. Replace belt | |
| BELT BROKEN (Note: Identify and correct problem before new belt is installed) | 1. Incorrect belt tension | 1. Replace Inspect/Replace tensioner if necessary |
| 2. Tensile member damaged during belt installation | 2. Replace belt | |
| 3. Severe misalignment | 3. Align pulley(s) | |
| 4. Bracket, pulley, or bearing failure | 4. Replace defective component and belt | |
| NOISE (Objectionable squeal, squeak, or rumble is heard or felt while drive belt is in operation) | 1. Incorrect belt tension | 1. Inspect/Replace tensioner if necessary |
| 2. Bearing noise | 2. Locate and repair | |
| 3. Belt misalignment | 3. Align belt/pulley(s) | |
| 4. Belt to pulley mismatch | 4. Install correct belt | |
| 5. Driven component induced vibration | 5. Locate defective driven component and repair | |
| 6. Belt flat surface coming apart | 6. Replace belt | |
| TENSION SHEETING FABRIC FAILURE (Woven fabric on outside, circumference of belt has cracked or separated from body of belt) | 1. Tension sheeting contacting stationary object | 1. Correct rubbing condition |
| 2. Excessive heat causing woven fabric to age | 2. Replace belt | |
| 3. Tension sheeting splice has fractured | 3. Replace belt | |
| CORD EDGE FAILURE (Tensile member exposed at edges of belt or separated from belt body) | 1. Incorrect belt tension | 1. Inspect/Replace tensioner if necessary |
| 2. Belt contacting stationary object | 2. Replace belt | |
| 3. Pulley(s) out of tolerance | 3. Replace pulley | |
| 4. Insufficient adhesion between tensile member and rubber matrix | 4. Replace belt |
ACCESSORY DRIVE BELT DIAGNOSIS CHART
Scheme 18
| 1 - IDLER PULLEY |
|---|
| 2 - P/S PUMP |
| 3 - A/C COMPRESSOR |
| 4 - CRANKSHAFT |
| 5 - TENSIONER |
| 6 - GENERATOR |
| CAUTION | Do not let tensioner arm snap back to the freearm position, sever damage may occur to the tensioner. |
- Rotate belt tensioner (5) counterclockwise until it contacts it's stop. Remove belt, then slowly rotate the tensioner into the freearm position.
Scheme 19
- Remove the air intake tube between the intake manifold and the air filter assembly.
- Insert a suitable square drive ratchet into the square hole on the belt tensioner arm (7).
- Release the belt tension by rotating the tensioner (7) clockwise . Rotate the belt tensioner until the accessory drive belt (4) can be removed from the pulleys.
- Remove the accessory drive belt (4).
- Gently release the tensioner (7).
Scheme 20
| 1 - IDLER PULLEY |
|---|
| 2 - WATER PUMP |
| 3 - P/S PUMP |
| 4 - A/C COMPRESSOR |
| 5 - CRANKSHAFT |
| 6 - TENSIONER |
| 7 - GENERATOR |
| CAUTION | Do not let the tensioner arm snap back to the freearm position, sever damage may occur to the tensioner. |
- Disconnect negative battery cable from battery.
- Rotate accessory drive belt tensioner (6) counterclockwise until it contacts it's stop. Remove accessory drive belt, then slowly rotate the tensioner into the freearm position.
INSPECTION
Hold cap at eye level, right side up. The vent valve at bottom of cap should open. If rubber gasket has swollen and prevents vent valve from opening, replace cap.
Hold cap at eye level, upside down. If any light can be seen between vent valve and rubber gasket, replace cap. Do not use a replacement cap that has a spring to hold vent shut. A replacement cap must be the type designed for a coolant reserve/overflow system with a completely sealed diaphragm spring and a rubber gasket. This gasket is used to seal to radiator filler neck top surface. Use of proper cap will allow coolant return to radiator.
COOLANT CONCENTRATION TESTING
Coolant concentration should be checked when any additional coolant was added to system or after a coolant drain, flush and refill. The coolant mixture offers optimum engine cooling and protection against corrosion when mixed to a freeze point of -37°C (-34°F) to -46°C (-50°F). The use of a hydrometer or a refractometer can be used to test coolant concentration.
A hydrometer will test the amount of glycol in a mixture by measuring the specific gravity of the mixture. The higher the concentration of ethylene glycol, the larger the number of balls that will float, and higher the freeze protection (up to a maximum of 60% by volume glycol).
A refractometer Tool 8286. See Cooling - Special Tools will test the amount of glycol in a coolant mixture by measuring the amount a beam of light bends as it passes through the fluid.
Some coolant manufactures use other types of glycols into their coolant formulations. Propylene glycol is the most common new coolant. However, propylene glycol based coolants do not provide the same freezing protection and corrosion protection and is not recommended.
| CAUTION | Do not mix types of coolant - corrosion protection will be severely reduced. |
Scheme 21
| 1 - RADIATOR FAN ASSEMBLY |
|---|
| 2 - ELECTRICAL CONNECTOR |
| 3 - UPPER RADIATOR HOSE |
- Disconnect negative battery cable.
- Partially drain cooling system. See «Cooling - Standard Procedure»(ref-353989-S26378580252010011300000) .
- Remove the air filter housing assembly. Refer to «Engine/Air Intake System/BODY, Air Cleaner - Removal»(ref-354006-S27420535772010011300000) .
- Remove the upper radiator hose (3).
- Disconnect the cooling fan electrical connector (2).
- Remove the cooling fan mounting bolts.
- Remove the radiator cooling fan assembly (1) from vehicle.
- Remove the fan blade from the fan motor.
- Remove the fan motor from cooling fan shroud.
Inspect the radiator tanks for cracks, broken or missing fittings also inspect the joint where the tanks seam up to the radiator core for signs of leakage and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing cooling fins. Inspect the core for bent or damaged cooling tubes.