If these modified engine performancecharacteristics persist for an extendedperiod and either the service engine soonor powertrain malfunction, reduced power,electronic throttle control light isilluminated, have the system checked byan authorized dealer.
Service engine soon
Powertrain malfunction, reducedpower, electronic throttle control
Diesel Lubrication System
It is important to change the engine oil atthe recommended service intervals orwhen indicated by the information displayto maintain oil viscosity. Extending the oiland filter change interval beyond therecommended interval can negativelyaffect engine performance, fuel economyand engine life. See Engine Oil Check(page 227).
Engine and secondary cooling system
The cooling system contains a primarycooling loop to cool the engine and asecondary cooling loop to cool thetransmission, charge air, and fuel. Thecoolant serves three primary purposes: toprovide heat transfer, freeze pointprotection, and corrosion protection usingadditives.
Vehicles with diesel engines typically areused to carry heavy loads and accumulatemileage rapidly. These two factors maycause the additives in the coolant to wearout in a shorter time. You can find moreinformation about coolant additives andcoolant change intervals in the coolantchapter. See General MaintenanceInformation (page 325). Operating theengine with insufficient coolant or coolantadditive can cause severe engine damage.
Selective catalytic reduction system
Your vehicle is equipped with a selectivecatalytic reduction system designed toreduce emission levels of nitrogen oxidesfrom the exhaust of your diesel engine. Thissystem relies on the use of Diesel ExhaustFluid (DEF) that you must replenish atcertain intervals. Failure to maintain properDEF levels or if the DEF becomescontaminated will result in vehicle speedlimitations or result in your vehicle enteringan idle-only mode. See SelectiveCatalytic Reductant System (page 120).
Minor Troubleshooting Guide
If the engine won’t crank
WARNING: Battery posts,terminals and related accessoriescontain lead and lead compounds. Washhands after handling.
Turn on the headlights. If the lights are dim,do not go on at all or when the ignition isturned to the start position, the lightsbecome dim or go out, the batteryconnections may be loose or corroded, orthe battery may be discharged. If there isa clicking or stuttering sound coming fromthe engine compartment when you turnthe key to the start position, this may alsoindicate a loose or corroded batteryconnection.
Check the battery connections at thebattery posts, cable connection to theengine grounding point and at the starterconnection.
If you suspect a discharged battery, haveit checked and corrected.
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Engine starting (with parking brake applied)
Check the gauge (diesel engine) or indicator light (gasolineengine) to verify the alternator is charging.Voltmeter
Inspect for excessive free play in the steering linkages. Thesteering wheel should have less than 2 in (5 cm) of free playat its rim.
Steering linkage free play
Verify the parking brake holds the vehicle by gently trying topull forward with the parking brake applied.Parking brake
Verify operation using the following procedure. Chock thewheels, if necessary. Push in the parking brake and, ontractors, push in the tractor parking brake knob:
Air brakes
1. Verify the air compressor or governor cutout pressure isapproximately 120 psi (827 kPa).
2. Turn off the engine, and then turn the key back to the onposition (without starting the engine).
3. Without the brake pedal applied, note the air pressure dropfor one minute. It should be less than 2 psi (14 kPa) for singlevehicles and 3 psi (21 kPa) for combination vehicles.
4. Press and hold the brake pedal with 90 psi (621 kPa) ormore. Make sure there is no more than a 3 psi (21 kPa) perminute leak for single vehicles and a 4 psi (28 kPa) minuteleak for combination vehicles.
5. Pump the brake pedal to deplete the system of air pressure.The warning light and tone should turn on at 57 psi (393 kPa).
6. Pump the brake pedal and make sure the parking brakeand trailer parking brake knobs pop out at 20 psi (138 kPa)or higher.
Verify that the fluid level is in the proper operating range. SeeAutomatic Transmission Fluid Check (page 243).Automatic transmissionfluid
Front of vehicle
Verify all exterior lights illuminate and are clean.Lights
Check headlights function on high and low beam.
Verify reflectors are clean, unbroken and of proper color (redon rear, amber elsewhere).
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2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingVehicle Inspection Guide
