Cooling System [3.0L]: Overview Mazda Tribute II

ENGINE COOLING DESCRIPTION/OPERATION - 3.0L

Note. The addition of Cooling System Stop Leak Pellets darken coolant from yellow to golden tan.

The cooling system consists of the following components

1. Block heater (if equipped)
2. Radiator
3. Bypass tube
4. Pressure relief cap
5. Degas bottle
6. Radiator draincock
7. Coolant pump
8. Coolant temperature indicator sender unit
9. Thermostat housing CAUTION: Engine coolant provides freeze protection, boil protection, cooling efficiency and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle. When adding engine coolant, use a 50/50 mixture of engine coolant and distilled water.

To maintain the integrity of the coolant and the cooling system

1. Add Mazda Premium Gold Engine Coolant or equivalent meeting Mazda Specification (yellow color). Do not mix coolant types.
2. Do not add/mix orange-colored Mazda Specialty Orange Engine Coolant or equivalent meeting Mazda specifications or green colored Mazda Premium Engine Coolant meeting Mazda specifications or equivalent. Mixing coolants may degrade the coolant's corrosion protection.
3. Do not add alcohol, methanol, brine or any engine coolants mixed with alcohol or methanol antifreeze. These can cause engine damage from overheating or freezing.
4. Mazda does NOT recommend the use of recycled coolant in vehicles originally equipped with Mazda Premium Gold Engine Coolant since a Mazda-approved recycling process is not yet available.
5. Used engine coolant should be disposed of in a appropriate manner. Follow your community's regulations and standards for recycling and disposing of automotive fluids. NOTE: Black arrows indicate hot, white arrows indicate cold.

Coolant Flow Diagram

Scheme 17

Principles Of Operation

Engine coolant flows primarily from the engine to the radiator circuit and back to the coolant pump. From the coolant pump, coolant is sent through the engine block and cylinder heads. A separate circuit from the engine also feeds the heater core with coolant. The coolant pump is operated by engine rotation through a pulley which is driven by the accessory drive belt, a belt driven by a pulley attached to the camshaft, or a sprocket driven by the timing chain to circulate the coolant. The coolant thermostat is a control valve actuated by coolant temperature. When the thermostat is closed, coolant flow bypasses the radiator circuit and returns to the coolant pump. When the thermostat is opened, coolant is allowed to flow through the radiator circuit in order to transfer engine generated heat to the outside air.

The degas bottle, if equipped, holds surplus coolant and removes air from the cooling system, which reduces hot spots. It also allows for coolant expansion and system pressurization, replenishes coolant to the cooling system and serves as the location for service fill.

The cooling fan draws air through the radiator to help cool the system coolant as it passes through the radiator.

The coolant expansion tank, if equipped, holds surplus coolant, allows for coolant expansion and replenishes coolant to the cooling system. It is equipped with a non-pressurized cap which allows coolant to be added to the tank to keep it filled to prescribed levels.

The cooling fan draws air through the radiator to help cool the system coolant as it passes through the radiator.

The thermostat monitor is a function of the PCM and is designed to verify correct thermostat operation. The monitor will be executed once per drive cycle and has a monitor run duration of 300-800 seconds. If a malfunction occurs, DTC P0125 or P0128 is set, and the malfunction indicator lamp will be illuminated.

For vehicle/engine specific information, see ENGINE COOLING DESCRIPTION/OPERATION - 3.0L.

Note. Vehicles have the pressure relief cap on the degas bottle and no radiator cap.

1. Verify the customer concern.
2. Visually check the engine coolant level at the degas bottle or coolant expansion tank when the system is cold.
3. Make sure the pressure relief cap is installed correctly.
4. Record any cooling system DTCs retrieved. Refer to «DTC INDEX - PCM»(/mazda/tribute/ii-2007-2011/remont/testing-diagnostics/#symptom-troubleshooting-engine-25l-30l) . For all other DTCs, see «DTC CHART - B, C AND U CODES»(/mazda/tribute/ii-2007-2011/remont/testing-diagnostics/#symptom-troubleshooting-engine-25l-30l) for appropriate descriptions. NOTE: Take note of any coolant odor or steam coming from cooling system components.
5. If the system coolant is filled correctly and no DTCs associated with fail-safe cooling are retrieved, verify the customer's concern by operating the engine to duplicate the condition. NOTE: Refer to the coolant flow diagram. See «ENGINE COOLING DESCRIPTION/OPERATION - 3.0L»(ref-348665-S04996080792009112700000).
6. Inspect to determine if any of the following mechanical or electrical concerns apply. VISUAL INSPECTION CHART Mechanical Electrical Leaks or weeps at: Hoses Tubes Clamp joints Quick connect couplings (if equipped) Gaskets O-rings Thermostat housing Radiator Pressure relief cap Water pump Heater core (wet floor or coolant odor in vehicle) Oil cooler (if equipped) Degas bottle (if equipped) Cylinder block core plugs (if equipped) Cylinder head core plugs (if equipped) Block heater (if equipped) Inoperative or damaged: Electric cooling fan (if equipped) Wiring, connectors, relays or modules Engine coolant temperature (ECT) sensor (if equipped) Cylinder head temperature (CHT) sensor (if equipped) Mass air flow (MAF) sensor Vehicle speed sensor (VSS) Cracked or damaged: Hoses Tubes Hose clamps Thermostat housing Radiator Pressure relief cap Cooling fan Water pump Degas bottle (if equipped) Oil cooler (if equipped) Cylinder block core plugs (if equipped) Cylinder head core plugs (if equipped) Block heater (if equipped) Restricted airflow through the A/C condenser/radiator Drive belt loose, worn or installed incorrectly Broken or weak drive belt tensioner Excessive white or light gray exhaust smoke (may have burnt coolant odor) Coolant in engine oil Engine oil in coolant
7. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary. Test the system for normal operation.
8. Inspect the coolant condition. Inspect the coolant color. If Mazda Premium Gold Engine Coolant has a clear or pale yellow color, this indicates higher water content than required. Test the engine coolant freezing point range with the Battery/Anti-Freeze Tester. The freezing point should be in the range -45°C to -23°C (-50° to -10°F). If the vehicle is driven in cold climates less than -36°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 ethylene glycol to distilled water. A pale green color indicates incorrect coolant (green in color) may have been added to the system. Use of incorrect (green in color) coolant degrades the corrosion protection of Mazda Premium Gold Engine Coolant. Flush the system and refill with the correct mixture of distilled water and Mazda Premium Gold Engine Coolant. Dark brown could indicate a commercially available stop leak may have been used. Flush the system and refill with the correct mixture of distilled water and Mazda Premium Gold Engine Coolant. 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 Mazda Premium Gold Engine Coolant. An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system. A milky brown color may indicate that engine oil is entering the cooling system. Pressure test the cooling system. Refer to component tests in this service information. If engine oil is suspected, the cause of the leak may be internal to the engine. A red, orange or light green colored sheen on top of the coolant may indicate that transmission fluid is entering the cooling system. The cause may be a leaky radiator. Pressure test the cooling system. See component tests in this service information. If the engine coolant appearance is acceptable, test the engine coolant freezing point range with the Battery/Anti-Freeze Tester. The freezing point should be in the range -45°C to -23°C (-50°F to -10°F). If the vehicle is driven in cold climates less than -36°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 50/50 ethylene glycol to distilled water. Maximum coolant concentration is 60/40 for cold weather areas. Minimum coolant concentration is 40/60 for warm weather areas. Adjust coolant range and level if necessary: If coolant is low, add specified coolant mixture only. If the engine coolant tests too weak, remove some of the engine coolant and add undiluted 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. NOTE: If Cooling System Stop Leak Pellets are used, darkening of the Mazda Premium Gold Engine Coolant from yellow to golden tan will occur.
9. If an obvious cause for an observed or reported concern is found, correct the cause and test the system for normal operation before proceeding to the next step.
10. If the cause is not visually evident, connect the scan tool to the data link connector (DLC). NOTE: Make sure to use the latest scan tool software release.
11. If the scan tool does not communicate with the VCM: check the VCM connection to the vehicle. check the scan tool connection to the VCM. see «PINPOINT TEST 14: NO POWER TO THE SCAN TOOL»(ref-348628-S36403127022009112700000), to diagnose no power to the scan tool. NOTE: The vehicle communication module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM.
12. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. verify the scan tool operation with a known good vehicle. see «COMMUNICATIONS NETWORK»(ref-348648-S15156040162009112700000) to diagnose no response from the PCM.
13. Carry out the network test. If the scan tool responds with no communication for one or more modules, see «COMMUNICATIONS NETWORK»(ref-348648-S15156040162009112700000). If the network test passes, retrieve and record continuous memory DTCs.
14. Clear the continuous DTCs and carry out the self-test diagnostics for the generic electronic module (GEM).
15. If the DTCs recovered are related to the concern, go to «DTC INDEX - PCM»(/mazda/tribute/ii-2007-2011/remont/testing-diagnostics/#symptom-troubleshooting-engine-25l-30l) . For all other DTCs, see «DTC CHART - B, C AND U CODES»(/mazda/tribute/ii-2007-2011/remont/testing-diagnostics/#symptom-troubleshooting-engine-25l-30l) .
16. If no DTCs related to the concern are retrieved, see «VISUAL INSPECTION CHART»(ref-348665-S19355548932009112700000).

See also:
• DTC INDEX - PCM