E4NGINE,  FUEL, 4-1. Engine, TM  10-3930-643-34 EXHAUST  AND  COOLING  TROUBLESHOOTING  AND  MAINTENANCE. Fuel,  Exhaust  and  Cooling  Troubleshooting. MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION f. ENGINE  KNOCKS. Step 1. Check for bad gaskets or crack in manifolds, replace as necessary, refer to paragraph 4-11. Step 2. Perform  Intake  Manifold  Pressure  Boost  Test,  refer  to  paragraph 4-1.j. Step 3. Check low intake manifold pressure, refer to paragraph 4-1.h. If any knocks or sound of metal to metal contact exists, and if manifolds do not leak and boost pressure meets specifications, shut engine off immediately  and  contact  General  Support. g. HIGH INTAKE MANIFOLD PRESSURE. Check for defective or incorrectly adjusted fuel injection pump, refer to paragraph 4-14. If repair is necessary, contact General Support. h. LOW INTAKE MANIFOLD PRESSURE. Step 1. Check for defective or incorrectly adjusted fuel injection pump, refer to paragraph 4-14. Step 2. Check for defective intake or exhaust manifolds or gaskets, refer to paragraph 4-11. If manifolds and gaskets are satisfactory, proceed to step 3. Step 3. Check fuel injectors, refer to paragraph 4-12. If repair is necessary, contact General Support. Step 4. Check  turbocharger,  refer  to  paragraph  4-15. If repair is necessary, contact General Support. 4-9