Operate the engine at rated RPM and load. Record
the intake manifold temperature.
Measure the ambient temperature at least two feet
in front of the vehicle.
The maximum temperature differential must not be
greater than 25°C [45°F].
If the temperature differential is greater than 25° C
[45° F], check the charge air cooler for dirt and
debris on the fins, and clean as necessary. If the
problem still exists, check the cooler for internal
To check the charge air cooler for cracked tubes or
header, remove the inlet and outlet hoses from the
Remove the charge air cooler.
Using service Tool No. 3824556, install a cap over
the outlet side of the cooler. Install a pressure gauge
and a shop air supply line to the inlet side of the