Normal inlet manifold pressure with high exhaust temperature can be caused by cooler core fin blockage. Clean the cooler core fins, see Visual Inspection for the cleaning procedure to use. Low inlet manifold pressure and high exhaust manifold temperature can be caused by any of the conditions that follow:
1. A plugged air cleaner. Clean or replace the air cleaner as needed.
2. A blockage in the air lines between the air cleaner and turbocharger. All restrictions must be removed.
3. Cooler core leakage. Pressure test the cooler core, see Aftercooler Core Leakage for the correct procedure to use and repair or replace parts as needed.
4. Leakage from the pressure side of the induction system. Check and repair leaks.
5. Inlet manifold leak. Check for loose, missing and damaged fittings or plugs. Also check the manifold to cylinder head gaskets.