Problems Requiring Disassembly

1. Incorrect or damaged radiator fan.
2. Worn or damaged emission system components.
^ Could cause overheating at idle.
^ Damaged positive crankcase ventilation (PCV) valve, thermal vacuum valve (TVV), or engine coolant temperature (ECT) sensor.
3. Pressure check the cooling system with the pressure cap installed.
^ Shows if the pressure cap leaks because of radiator filler neck damage.
4. Worn or damaged water pump.
^ Impeller vanes eroded or broken.
^ Worn or damaged bearing and/or seal. Check for shaft or bearing play.
5. Plugged radiator tubes.
^ Perform a flow check.
6. Internal system leaks.
^ Cylinder head gasket.
^ Cracked block.
^ Timing chain cover.
^ Intake manifold gasket.
7. Plugged coolant passages in the cylinder heads.
^ Visual check.