PINPOINT TEST A : PINPOINT TEST

Radiator Pressure relief cap Coolant pump leaking from weep hole Heater core Lower intake manifold Engine gaskets (may leak internally or externally) Degas bottle Cylinder block core plugs Cylinder head core plugs Block heater (if equipped)

WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.

A1 CARRY OUT INSPECTION AND VERIFICATION

Carry out Inspection and Verification.

Are any concerns present?

Yes	REPAIR as needed.
No	GO to A2

A2 CHECK THE ENGINE COOLANT LEVEL AND PRESSURE TEST THE ENGINE COOLING SYSTEM

NOTE: Allow the engine to cool before checking the engine coolant level.

Ignition OFF Visually inspect the engine coolant level at the degas bottle and adjust as necessary. Pressure test the engine cooling system. Refer to Component Tests, Cooling System Pressure Test in this section.

Does the engine cooling system leak externally?

Yes	REPAIR or INSTALL new components.
No	GO to A3

A3 CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK

Inspect the engine coolant in the degas bottle for signs of engine oil or transmission fluid.

Is engine oil evident in the coolant?

Yes	REFER to: Engine (303-00 Engine System - General Information, Diagnosis and Testing).
No	GO to A4

A4 CHECK THE ENGINE OIL FOR COOLANT

Remove the oil level indicator from the engine.

Is coolant evident in the oil?

Source reference 583

2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.