TANK GP-MTG& 4416337 - Caterpillar

Illustration 4 g01448617
Turbocharger with wastegate
(23) Actuating lever
(24) Canister
(25) Line (boost pressure)
(26) Pressure relief orifice When the engine is operating under conditions of low boost, a spring pushes on a diaphragm in canister (24). This action moves actuating lever (23) in order to close the valve of the wastegate. Closing the valve of the wastegate allows the turbocharger to operate at maximum performance.
Illustration 5 g01448618
(27) Inlet manifold
(28) Wastegate solenoid Wastegate solenoid (28) allows the engine ECM to more precisely regulate the boost pressure to the engine. By closing or partially closing the wastegate solenoid, the ECM can increase the boost pressure. Typical wastegates will limit boost pressure to a preset limit. Wastegate solenoid (28) blocks air from reaching the wastegate and this allows boost pressure to increase. Air is routed from inlet manifold (27) to wastegate solenoid (28). The wastegate solenoid (28) senses the air pressure of the inlet air and the wastegate solenoid adjusts the wastegate accordingly. The pressure relief orifice (26) allows air to escape from the line (boost pressure) when the pressure is too high.As the boost pressure through line (25) increases against the diaphragm in canister (24), the valve of the wastegate is opened. When the valve of the wastegate is opened, the rpm of the turbocharger is limited by bypassing a portion of the exhaust gases. The exhaust gases are routed through the wastegate which bypasses the turbine wheel of the turbocharger.Note: The turbocharger with a wastegate is preset at the factory and no adjustment can be made.
When the wastegate solenoid is deactivated, the wastegate is closed. This allows the engine to obtain the maximum boost in pressure.
When the wastegate solenoid is activated, the wastegate is open. This allows the engine to control the boost of the pressure.Valve System Components
Illustration 6 g01448714
Valve system components
(29) Rocker arms
(30) Bridge
(31) Spring
(32) Pushrods
(33) Exhaust valve
(34) Inlet valves
(35) Lifter
(36) Camshaft lobe The valve system components control the flow of inlet air into the cylinders during engine operation. The valve system components also control the flow of exhaust gases out of the cylinders during engine operation.The crankshaft gear drives the camshaft gear through an idler gear. The camshaft must be timed to the crankshaft in order to get the correct relation between the piston movement and the valve movement.The camshaft has two camshaft lobes for each cylinder. The lobes operate the inlet and exhaust valves. As the camshaft turns, lobes on the camshaft cause lifters (35) to move pushrods (32) up and down. Upward movement of the pushrods against rocker arms (29) results in downward movement (opening) of valves (33) and (34).Each cylinder has two inlet valves and one exhaust valve. Valve springs (31) close the valves when the lifters move down.Air Inlet Heater
The engines are equipped with an electric heater that is located behind the air inlet elbow. The electric heater has two functions:
Aid in starting
Aid in white smoke cleanup during start-upUnder the proper conditions, the ECM turns on the electric heater. The following conditions are evaluated prior to activating the electric