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Blue Bird/Caterpillar C-7 Cold Starting Procedures

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johnjohnston User avatar

Caterpillar C-7 Cold Weather Starting

Recently with the cold weather snap and new product in service with the Caterpillar C-7 engine we have had questions arise regarding the start-ability in cold weather.

Page 3-4-5 of this article is Blue Bird’s “Service Update #S0307”, which was written to address engine cold start procedures with the “Vision” –
Please note that this should also apply to Blue Bird’s A3FE & A3RE Line of units with the C-7

With references made to Caterpillar’s “Operation and Maintenance Manual” we have attached pages directly from that manual and are on pages 6-7-8 of this article for your reference.

Several questions have also arisen as to the proper viscosity of oil used in the C-7 during the colder months of winter and for this reason we have attached those pages pertinent to oil viscosity and ambient temperature from the Caterpillar “Operation and Maintenance Manual” to pages 9-10-11-12 of this article. If you pay close attention to table #4 on page 10, you may wish to use lighter viscosity oil during our winter months to decrease the effort needed to crank the engine over, but this will be dependant on the ambient temperature in your particular region of the state.

If you do not have the ability to use block heaters nor have inside storage you may wish to consider an alternative method such as a pre-heater.

Charging Issues with the Added Electrical Draw of the “Air Intake Heater”

The other issue that we have heard of is the draw created by the “Air Intake Heater” and the fact that it causes an added draw on the electrical system of approximately 90-100 amps.
We have included information on the “Air Intake Heater” from Caterpillar’s “ELECTRICAL & ELECTRONIC APPLICATION GUIDE” and included it in this article on page 13-14-15. As you can see from reading through the information, the “Air Intake Heater” is controlled by the ECM through the combined temperatures of the ambient air and coolant.
What may often times occur is that the “Air Intake Heater” will cycle on one the unit is running as the air temperature across the sensor may cool and the coolant may also cool when the thermostat of the engine opens.

What is recommended is that prior to starting the unit all additional electrical components (lights, heaters, etc.) are shut off. After the unit has been started and for approximately 2 minutes after the “Wait to Start” light has gone out all the additional electrical components can then be turned on and operated as normal. This procedure will help to eliminate the draw created by having all the electrical accessories AND the “Air Intake Heater” concurrently.














70
Operation Section
Engine Starting

Cold Weather Starting
Starting the engine and operation in cold weather is dependent on the type of fuel that is used, the oil viscosity, and other optional starting aids. For more information, refer to the Operation and Maintenance Manual, “Cold Weather Operation” topic (Operation Section).

Air Inlet Heater
DO NOT USE ETHER (starting fluids) unless specifically instructed to do so. If the engine is equipped with an Air Inlet Heater (electrically or fuel ignited manifold heater), DO NOT use ether (starting fluids) at any time. The use could result in engine damage and/or personal injury.
Note: There will be an indicator lamp on the dashboard of the vehicle that is marked “AIR INLET HEATER”.
For detailed information on the operation of the Air Inlet Heater, refer to System Operation, “Air Inlet and Exhaust”.
Use the following procedure in order to start the engine:
1. Engage the parking brake. Place the transmission in NEUTRAL. If the vehicle is equipped with a manual transmission, depress the clutch pedal in order to disengage the flywheel clutch. This reduces transmission drag and this prevents movement of the vehicle.
Depressing the clutch helps to reduce the battery drain. In cold weather, this can mean the difference between starting the engine and not starting the engine.
The “CHECK ENGINE/DIAGNOSTIC” lamp will flash while the engine is cranking. The lamp should turn off after proper engine oil pressure is achieved. If the lamp fails to flash, notify your authorized Caterpillar dealer. If the lamp continues to flash, the ECM has detected a problem in the system. Refer to the Operation and Maintenance Manual, “Engine Diagnostics” topic (Operation Section).
2. Turn the keyswitch to the ON position. The air inlet heater can preheat the system in order to improve cold weather starting.



71
Operation Section
Engine Starting

Note: The “AIR INLET HEATER” indicator lamp will flash for a minimum of two seconds regardless of the coolant temperature. If the “AIR INLET
HEATER” indicator lamp flashes for more than two seconds, wait until the indicator lamp stops flashing (approximately 30 seconds) before attempting to start the engine. If the indicator lamp continues to flash, the ECM will control the air inlet heater during a restart of the engine.
Restarting the engine at this point can cause excessive white smoke.
Note: A buzz may be heard while the air inlet heater is engaged. This is the sound of the fuel injectors that are being exercised in preparation for starting.
NOTICE
Do not engage the starting motor when flywheel is turning. Do not start the engine under load. If the engine fails to start within 30 seconds, release the starter switch or button and wait two minutes to allow the starting motor to cool before attempting to start the engine again.
3. Turn the keyswitch to the START position in order to crank the engine. The air inlet heater will turn ON if the sum of the coolant temperature and the inlet air temperature is less than 25 _C (77 _F). Do not push the throttle or do not hold the throttle downward while the engine is cranked. The system will automatically provide the correct amount of fuel in order to start the engine. If the engine does not start after 15 to 20 seconds of cranking, release the keyswitch. If the sum of the coolant temperature and the inlet air temperature is less than
25 _C (77 _F), the preheat for the air inlet heater will restart. Turn the
keyswitch to the OFF position. Allow the starting motor to cool for two minutes. Repeat Steps 2 and 3.
NOTICE
Oil pressure should rise within 15 seconds after the engine starts. Do not increase engine speed until the oil pressure gauge indicates normal. If oil pressure is not indicated on the gauge within 15 seconds, DO NOT operate the engine. STOP the engine, investigate and correct the cause.


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Operation Section
Engine Starting

4. Release the keyswitch to the ON or RUN position immediately after the engine starts. After the engine starts, check in order to ensure that the transmission is still in the NEUTRAL position and release the clutch pedal (manual transmission). Once a normal engine oil pressure and air pressure are reached, the vehicle may be operated at a light load and speed. After the engine has started, the air inlet heater may continue to operate in a “Continuous” mode and/or in an “Intermittent” mode. The air inlet heater will turn OFF when the sum of the coolant temperature and the air inlet temperature exceeds 35 _C (95 _F). If the engine is operated with a low load, the engine will reach normal operating temperature sooner than idling the engine with no load. When the engine is idled in cold weather, increase the engine rpm to approximately 1000 to 1200 rpm. This will warm up the engine more quickly. Do not exceed the recommended rpm in order to increase the speed of the warm-up. Limit unnecessary idle time to ten minutes.
Starting Problems
An occasional starting problem may be caused by one of the following items:
• Low battery charge
• Lack of fuel
• Problem with the wiring harness
If the engine fuel system has been run dry, fill the fuel tank and prime the fuel system. Refer to the Operation and Maintenance Manual, “Fuel System - Prime” topic (Maintenance Section).
If the other problems are suspected, perform the appropriate procedure in order to start the engine.









106
Maintenance Section
Lubricant Specifications
NOTICE
Operating Direct Injection (DI) diesel engines with fuel sulfur levels over 1.0 percent may require shortened oil change intervals in order to help maintain adequate wear protection.
Lubricant Viscosity Recommendations for Direct
Injection (DI) Diesel Engines
The proper SAE viscosity grade of oil is determined by the minimum ambient temperature during cold engine start-up, and the maximum ambient temperature during engine operation.
Refer to Table 4 (minimum temperature) in order to determine the required oil viscosity for starting a cold engine.
Refer to Table 4 (maximum temperature) in order to select the oil viscosity for engine operation at the highest ambient temperature that is anticipated.
Note: Generally, use the highest oil viscosity that is available to meet the requirement for the temperature at start-up.
If ambient temperature conditions at engine start-up require the use of multigrade SAE 0W oil, SAE 0W-40 viscosity grade is preferred over SAE 0W-20 or SAE 0W-30.
Note: SAE 10W-30 is the preferred viscosity grade for the following diesel engines when the ambient temperature is above −18 _C (0_F).
• C7
• C9
• 3116
• 3126
107
Maintenance Section
Lubricant Specifications











Table 4

Engine Oil Viscosities for Ambient Temperatures (1)
Ambient Temperature
Viscosity Grade Minimum Maximum
SAE 0W-20 -40 C (-40 F) 10 C (50 F)
SAE 0W-30 -40 C (-40 F) 30 C (86 F)
SAE 0W-40 -40 C (-40 F) 40 C (104 F)
SAE 5W-30 -30 C (-22 F) 30 C (86 F)
SAE 5W-40 -30 C (-22 F) 50 C (122 F)
SAE 10W-30(2) -18 C (0 F) 40 C (104 F)
SAE 10W-40 -18 C (0 F) 50 C (122 F)
SAE 15W-40 -9.5 C (15 F) 50 C (122 F)
(1) Refer to this publication, “Engine Oil (Recommendations)” for recommendations of diesel engine oil type.
(2) SAE 10W-30 is the preferred viscosity grade for the 3116,
3126, , C7, and C9 diesel engines when the ambient temperature is above −18 _C (0 _F).
Note: Supplemental heat is recommended below the minimum recommended ambient temperature.


Synthetic Base Stock Oils
SMCS Code: 1300; 1348; 7581
Synthetic base oils are acceptable for use in Caterpillar engines if these oils meet the performance requirements that are specified for the engine compartment.
Synthetic base oils generally perform better than conventional oils in the following two areas:
• Synthetic base oils have improved flow at low temperatures especially in arctic conditions.
• Synthetic base oils have improved oxidation stability especially at high operating temperatures.
108
Maintenance Section
Lubricant Specifications
Some synthetic base oils have performance characteristics that enhance the service life of the oil. However, Caterpillar does not recommend the automatic extension of oil change intervals for any type of oil. Oil change intervals for Caterpillar engines can only be adjusted after an oil analysis program that contains the following tests: oil condition and wear metal analysis (Caterpillar’s S•O•S oil analysis), trend analysis, fuel consumption, and oil consumption.

Re-refined Base Stock Oils
SMCS Code: 1300; 7581
Re-refined base stock oils are acceptable for use in Caterpillar engines if these oils meet the performance requirements that are specified by Caterpillar. Re-refined base stock oils can be used exclusively in finished oil or in a combination with new base stock oils. The US military specifications and the specifications of other heavy equipment manufacturers also allow the use of re-refined base stock oils that meet the same criteria.
The process that is used to make re-refined base stock oil should adequately remove all wear metals that are in the used oil and all additives that are in the used oil. The process that is used to make re-refined base stock oil generally involves the processes of vacuum distillation and hydrotreating the used oil. Filtering is inadequate for the production of high quality re-refined base stock oils from used oil.

Cold Weather Lubricants
SMCS Code: 1300; 1348; 7581
When an engine is started and an engine is operated in ambient temperatures below −20 _C (−4 _F), use multigrade oils that are capable of flowing in low temperatures.
These oils have lubricant viscosity grades of SAE 0W or SAE 5W.
When an engine is started and operated in ambient temperatures below −30 _C (−22 _F), use a synthetic base stock multigrade oil with a 0W viscosity grade or with a 5W viscosity grade. Use an oil with a pour point that is lower than −50 _C (−58 _F).
109
Maintenance Section
Lubricant Specifications
The number of acceptable lubricants is limited in cold weather conditions. Caterpillar recommends the following lubricants for use in cold weather conditions:
First Choice – Use one of the following oils that is licensed by API: CI-4 and CH-4. Global DHD-1 is also acceptable. The lubricant viscosity grade must be one of the following grades: SAE 0W-20, SAE 0W-30, SAE0W-40, SAE 5W-30, and SAE 5W-40.
Second Choice – Use a CG-4 oil that is licensed by the API. The lubricant viscosity grade should be one of the following grades: SAE 0W20, SAE 0W30, SAE 0W40, SAE 5W30, and SAE 5W40.

Aftermarket Oil Additives
SMCS Code: 1300; 1348; 7581
Caterpillar does not recommend the use of aftermarket additives in oil. It is not necessary to use aftermarket additives in order to achieve the engine’s maximum service life or rated performance. Fully formulated, finished oils consist of base oils and of commercial additive packages.
These additive packages are blended into the base oils at precise percentages in order to help provide finished oils with performance characteristics that meet industry standards.
There are no industry standard tests that evaluate the performance or the compatibility of aftermarket additives in finished oil. Aftermarket additives may not be compatible with the finished oil’s additive package, which could lower the performance of the finished oil. The aftermarket additive could fail to mix with the finished oil. This could produce sludge in the crankcase. Caterpillar discourages the use of aftermarket additives in finished oils.
To achieve the best performance from a Caterpillar engine, conform to the following guidelines:
• Select the proper Caterpillar oil or a commercial oil that meets the “EMA Recommended Guideline on Diesel Engine Oil” or the recommended API classification.
• See the appropriate “Lubricant Viscosities” table in order to find the correct oil viscosity grade for your engine.




11.0 Inlet Air Heater, Lamp and Relay Operation

The Inlet Air Heater (IAH) is used to improve cold start capability of the engine and to reduce white smoke. The ECM controls the Inlet Air Heater Grid and Inlet Air Heater Lamp through the Inlet Air Heater Relay. The heater and relay are installed on the engine at Caterpillar.
The Inlet Air Heater operation is determined at three different times: Power Up/Preheat, Engine Cranking and Engine Running. This operation is based on measured engine temperatures and affected by operational conditions including vehicle speed and service brake pedal position. If there is an active vehicle speed sensor fault the ECM will assume that the vehicle speed is above 5 mph and will disable the Intake air Heater when the Service Brake is applied.

11.1 Inlet Air Heater Relay Electrical Specifications

The OEM is responsible for connecting the contact side of the Inlet air heater relay to battery voltage. Recommended circuit protection for this connection is 130 Amps with a circuit load of 100 Amps continuous. The Inlet Air Heater Relay has a maximum ‘On’ time of 7 minutes. Minimum required wire size is 4 AWG.

11.4 ECM Power Up and Preheat Cycle

If the SUM of the Coolant Temperature and Inlet Manifold Air Temperature is less than 136°F or 40°C and the engine is being operated below 5500 feet (1678 meters) of elevation, the ECM will turn the Inlet Air Heater relay output ON for 30 seconds as a preheat cycle. If the engine is being operated at elevations higher than 5500 feet (1678 meters) the sum of the Coolant Temperature and Inlet Manifold Air Temperature must only be less than 160°F or 53°C in order to compensate for the extreme altitude operation.
NOTE: DO NOT convert the sum of the temperatures!!! The temperatures MUST be converted before summing!
The ECM adds Coolant Temperature and Inlet Manifold Air Temperature as measured in centigrade. In order to get the correct conversion of the summed value in Fahrenheit, each temperature must first be converted to Fahrenheit and then added together as follows:
([Coolant Temperature °C] X 1.8 +32) + ([Inlet Manifold Air Temperature °C] X 1.8 +32) = sum in Fahrenheit.
The Heater and Heater Lamp will turn ON, and then turn OFF when the cycle is complete. If the operator attempts to start the engine before the 30 second preheat cycle ends, the ECM will continue to control the Heater during engine cranking.

11.5 Engine Cranking Cycle

When the engine is cranking, the Heater will turn ON if the SUM of the Coolant Temperature and Inlet Manifold Air Temperature is less than 136°F or 40°C at elevations below 5500 feet (1678 meters), and stay ON while cranking. If the engine fails to start the Heater will activate for 30 seconds (preheat cycle is restarted). At elevations above 5500 feet (1678 meters) the SUM of the Coolant Temperature and Inlet Manifold Air Temperature must only be less than 160°F or 53°C in order to compensate for the extreme altitude operation.

11.6 Engine Running Cycle

After the engine has started, the Inlet Air Heater operation is determined by the same combination of both the Inlet Manifold Air Temperature and Coolant Temperature.
The Engine Running Cycle has two segments, a continuous mode followed by an On/Off cycling mode.
The Continuous ON mode lasts for a maximum of seven minutes. The On/Off cycle mode can last for a maximum of 13 minutes. During the On/Off cycle mode, the Heater is cycled ON and OFF for ten seconds. The Inlet Air Heater will turn OFF anytime the SUM of the Inlet Manifold Air Temperature and Coolant Temperature exceeds 126°F or 40°C if the engine is being operated below 5500 feet (1678 meters) of elevation. If the engine is being operated at elevations higher than 5500 feet (1678 meters), the Heater will turn OFF anytime the SUM of the Inlet Manifold Air Temperature and Coolant Temperature exceeds 178°F or 63°C.

11.7 IAH and Active Engine Diagnostics

Whenever there is an Active Open or Short Circuit Diagnostic Code for the Coolant Temperature Sensor, the Heater will activate if the Inlet Manifold Air Temperature is less than 50°F (10°C). For an Active Inlet Manifold Air Temperature Sensor Diagnostic, the Heater will activate if Coolant Temperature is less than 104°F (40°C).

2.8 IAH and Starting Aid Interaction

At key switch On, the Inlet Air Heater will not be activated if the Starting Aid Output is programmed to Automatic and the inlet air temperature is below 0 Deg C. The Inlet Air Heater will not be activated if the Starting Aid circuit is activated. When the Starting Aid Output is programmed to Automatic, the Inlet Air Heater will not be activated until the engine is running and the starting Aid output has been turned off for 5 seconds.


As "Computer Illiterate" as I am some of this document did not transfer and I could not "Attach" it. Please call us for a copy at 315-687-3969-Service Dept

Thanks,
John Johnston

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