• 2015

Replacing a 5.7L HEMI® Engine

Engine replacement is not a common procedure, but when it needs to be done, FCA US LLC has the complete engine for the task. This year, Mopar® announced the availability of an all-new 5.7L HEMI® engine 2003-2008 long block. And, it’s available with (P/N 68266874AA) or without (P/N 68266873AA) the multi-displacement system (MDS) hardware for the same price*. In this article we will discuss the 2008 Dodge Charger.


A long block engine includes the complete short block fitted with pistons and rings, crankshaft, main and rod bearings, plus complete cylinder heads, camshaft, valve lifters and pushrods.

Not included with the long block assembly are the water pump, front cover, fuel injection system, oil pan, oil pressure sensor, intake manifold and intake system. Note: special care should be taken not to damage the oil pressure sensor when installing the long block.


Before starting the engine removal procedure, the hood, cowl top panel and strut tower support must be removed to Figure1gain clear access to the engine (Figure 1). Also, all of the ancillary engine components that will be used on the new long block must be removed. Begin by removing the engine covers, release the fuel system pressure, then disconnect the negative battery cable. Next, remove the entire air intake system, the accessory drive belt, the cooling fan and the A/C compressor. Disconnect the A/C liquid lines and suction lines. Be sure to install plugs, or tape over the opened end of these lines.

On the bottom side of the engine, remove the heat shield, the generator and the support bracket. Then, remove the power steering pump (it’s not necessary to disconnect the power steering pump hoses from the power steering pump). Raise and support the vehicle and remove the belly pan. Drain the engine oil before draining the cooling system. Remove the lower radiator hose.

Two knock sensors are used on this engine and are bolted to the outside of the engine block below the exhaust manifold. The crank position sensor is located at the right rear side of the engine block. The oil pressure sensor is on the bottom side of the engine block. Remove these sensors to install in the new long block. Lower the vehicle.

On the top side of the engine, remove the upper radiator hose, heater hoses and camshaft position sensor. Next, remove all the ignition coil electrical connectors and fuel injector electrical connectors. Disconnect the MAP sensor, then remove the coolant temperature sensor and the ignition capacitor electrical connector. Now, the intake manifold and throttle body are removed as an assembly. After removing the right and left side wiring harnesses raise and support the vehicle.

Figure2Remove the front engine mount nuts (Figure 2). Separate the exhaust pipes from the exhaust manifolds (the exhaust manifolds will have to be removed from the engine after it is removed from the vehicle in order to be used on the new long block). Remove the heat shield and starter motor.

As all models have an automatic transmission, remove the inspection cover, then rotate the crankshaft in the clockwise direction until the converter bolts are accessible. Remove the bolts, the oil pan to transmission bolts and the bell housing to engine block bolts.

Lower the vehicle, remove the left coolant tube and install engine lift fixture P/N 8984B and adapter P/N 8984-UPD (Figure 3). Using a suitable engine hoist, separate the engine from the transmission and remove the engine from the vehicle.


Before installing the new long block, the ancillary components left on the engine after removal have to be removed andFigure3 installed on the new long block. These include components such as the exhaust manifolds, valve covers, water pump, front cover and oil pan. After transferring these components, install the engine lift fixture and adapter on the new engine (Figure 3).

Lift the long block off the engine stand and lower it into the engine compartment. If the vehicle has an automatic transmission, align the engine with the transmission. Install two transmission to engine block mounting bolts. Tighten finger tight. Lower the engine assembly until the engine mount studs rest in the frame brackets. Remove the engine hoist and adapter. If the vehicle is equipped with a manual transmission, install the transmission after the engine is lowered into the vehicle.

Raise and support the vehicle. Install the transmission to oil pan bolts (tighten to 29 ft.-lbs.), then install the remaining transmission to engine block mounting bolts (tighten all the bolts to 50 ft.-lbs.). Install the front engine mount retaining nuts (Figure 2) (tighten to 70 ft.-lbs.). On automatic transmission equipped vehicles, rotate the crankshaft in a clockwise direction and install all the torque converter to flex plate bolts (tighten finger tight). Note: correct length bolts MUST be used for attaching the converter to the flex plate.

Verify that the torque converter is pulled flush with the flex plate. Tighten the bolts to 65 ft.-lbs. Install the inspection cover (tighten the bolts to 8 ft.-lbs.).


Installing the long block into the vehicle and mating it with the automatic transmission is the most critical step when installing a new engine into a vehicle (mating the engine to a manual transmission isn’t nearly as complicated). After completing this task, the ancillary components, such as the starter, generator, intake manifold, exhaust system, et al, are installed on the long block. These components are installed in the reverse order of removal. The following are several points to keep in mind when installing the ancillary components:

  • Refer to the appropriate service manual for the correct torque tightening specificationsFigure4
  • When installing the intake manifold, ensure retaining bolts are tightened in the pattern shown (Figure 4)
  • Be sure that the array of engine sensors are installed on the new long block and that the electrical connectors are all connected
  • Connect the ignition coil and fuel injector electrical connectors
  • Charge the A/C system with refrigerant
  • Fill the cooling system with the correct amount of coolant mixed in the correct ratio with water
  • Fill the crankcase with oil
  • Reconnect the negative battery terminal block.

Finally, after installing the cowl and hood, test drive the vehicle to ensure that all the systems are operating correctly. Turn on the heater, then the A/C. Check the engine coolant temperature. After the road test, check all fluid levels and look for any fluid leakage from the engine block.

*The all-new 5.7L HEMI engine 2003-2008 long block is covered with the comprehensive Mopar 3-year/100,000-mile powertrain warranty that includes towing assistance and a dedicated tech support hotline.
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