| Tools Needed | Qty | |
| 4C-6500 Digital Thermometer | 1 | |
High inlet manifold air temperature will reduce the power output of the engine. High inlet manifold air temperature will also cause detonation.
The inlet manifold air temperature can be measured from more than one location.
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| Illustration 1 | g00819950 |
Plug near the front of the cylinder head | |
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| Illustration 2 | g00819936 |
Plugs on the aftercooler (1) Plug (2) Plug | |
Note: There will be a difference in the temperature that is measured at plug (1) and plug (2). This is because of the reduction of the air temperature through the aftercooler.
To measure the inlet manifold air temperature, use the 4C-6500 Digital Thermometer. Remove a plug near the front of the cylinder head or from the aftercooler. Insert a temperature probe in place of the plug. Measure the temperature when the engine is operating at full load.
Table 2 lists the maximum inlet manifold air temperatures. The temperatures are associated with different water temperature regulators for separate circuit aftercoolers.
| Maximum Inlet Manifold Air Temperature for G3400 Engines | |
| Water Temperature Regulator | Maximum Inlet Manifold Air Temperature |
32 °C (90 °F) (1) |
43 °C (110 °F) |
54 °C (130 °F) (1) |
65 °C (150 °F) |
| ( 1 ) | Water inlet to the aftercooler |