Engine Disassembly and Cleaning

Learning Goals

• ¦ Prepare an engine for removal.
• ¦ Remove an engine from a FWD and a RWD vehicle.
• ¦ Separate the engine into its basic components.
• ¦ Name the three basic cleaning processes.

This section covers the removal and installation of an engine. It also covers basic disassembly and general cleaning of the components. The material is presented so that it applies not only to engine rebuilding, but also to the replacement of individual parts when a total rebuild is not necessary. Complete disassembly and assembly of the engine block and cylinder head are covered in Sections 11 and 12.

Before removing the engine, clean it and the area around it. Also, check the service manual for the correct procedure for removing the engine from a particular vehicle. Make sure you adhere to all precautions given by the manufacturer.

REMOVING AN ENGINE

Make sure you have the tools and equipment required for the job before you begin. In addition to hand tools and some special tools, you will need an engine hoist or crane ( +++0-1) and a jack.

The basic procedures for engine removal vary, depending on whether the engine is removed from the bottom of the vehicle or through the hood opening. Many FWD vehicles require removal of the engine from the bottom, whereas most RWD vehicles require the engine to come out from the hood opening. The engine exit point is something to keep in mind while you are disconnecting and removing items in preparation for engine removal.

General Procedures:

When removing an engine, setting the vehicle on a frame contact hoist is recommended. When the vehicle is sitting on the floor, block the wheels so it does not move while you are working. Open the hood and put fender covers on both front fenders ( +++0-2). Once the vehicle is in position, relieve the pressure in the fuel system using the procedures given by the manufacturer.

+++0-1 To pull an engine out of a vehicle, the chain on the lifting crane is attached to another chain secured to the engine.

Customer Care: Make sure your hands, shoes, and clothing are clean before getting into a customer's car. Disposable seat and floor coverings should be used to help protect the interior.

+++0-4 Drain the engine's coolant and recycle it.

+++0-2 Before doing anything, put covers on the fenders.

+++0-3 After the negative battery cable is disconnected, tape the terminal end to prevent it from accidentally touching the battery.

+++0-5 If the transmission will be removed with the engine, disconnect all linkages, lines, and electrical connectors.

Battery--Install a memory saver before you disconnect the battery to prevent the vehicle's computers and other devices from losing what they have stored in their memory. Disconnect all negative battery cables ( +++0-3), tape their connectors, and place them away from the battery. If the battery will be in the way of engine removal, remove the positive cables and the battery.

Hood --The vehicle's hood will get in the way during engine removal. If the hinges allow the hood to be set straight up above the engine compartment, prop it in that position with wood or a broom. Make sure the hood is secure before proceeding. In many cases, the hood should be removed and set aside in a safe place on fender covers or cardboard. Make sure not to dam age the vehicle's paint while doing this. Before removing the hood, mark the location of the hinges on the hood. Then unbolt and remove the hood with the help of someone else.

SHOP TIPS -- Often the safest place to store the hood is on the vehicle's roof.

Fluids--Drain the engine's oil and remove the oil filter. Then drain the coolant from the radiator and engine block, if possible. To increase the flow of the coolant out of the cooling system, remove the radiator cap. Make sure the engine is cool before opening the coolant drain and before removing the radiator cap. After collecting the old coolant, recycle it. If the transmission will be removed with the engine, drain its fluid.

Underbody Connections--While you are under the vehicle to drain the fluids, disconnect the shift link age, transmission cooling lines, all electrical connections, vacuum hoses, and clutch linkages from the transmission. If the clutch is hydraulically operated, unbolt the slave cylinder and set it aside, if possible. If this is not possible, disconnect and plug the line to the cylinder.

Air-Fuel System--Remove the air intake ducts and air cleaner assembly. Disconnect and plug the fuel line at the fuel rail. If the engine is equipped with a return fuel line from the fuel pressure regulator, disconnect that as well. Make sure all fuel lines are closed off with pinch pliers or the appropriate plug or cap. Most late-model fuel lines have quick-connect fittings that are separated by squeezing the retainer tabs together and pulling the fitting off the fuel line nipple.

Disconnect all vacuum lines at the engine. Make sure these are labeled before disconnecting them.

Most automobiles have a vacuum wiring diagram decal under the hood. The diagram and the labels (these could be masking tape with the connecting point written on it) will make it easier to reconnect the hoses when the engine is reinstalled.

Now disconnect the throttle linkage at the throttle body and the electrical connector to the throttle position (TP) sensor.

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+++0-6 Disconnect and plug the fuel lines at the fuel rail and the pressure regulator.

+++0-7 An underhood decal showing the routing of vacuum lines for the vehicle.

In-tank pump; Supply fuel line; Return fuel line; Fuel filter; Pressure regulator; Fuel rail Injector

+++0-8 Before removing the drive belts, pay attention to the routing of each belt. Generator pulley; Power steering pump pulley, Water pump pulley, A/C compressor pulley, Crankshaft pulley Air pump pulley

+++0-9 Before unplugging the electrical wires between the engine and the vehicle, use masking tape as a label to identify all disconnected wires.

+++0-10 Typically the electric cooling fans can be removed as a unit with the radiator. Radiator Cooling fan motor; Condenser fan motor

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SHOP TIPS--Some technicians are using instant cameras or video recording cameras to help recall the locations of underhood items by taking pictures be fore work is started. This technique can be quite valuable considering how complex the under hood systems of current cars have become.

Accessories -- Remove all drive belts ( +++0 - 8). Unbolt and move the power steering pump and air-conditioning (A/C) compressor out of the way.

Don’t disconnect the lines unless it’s necessary.

If the pressure hoses at the A/C compressor must be disconnected, don’t loosen the fittings until the refrigerant has been captured by a refrigerant reclaimer/recycling machine. Once disconnected, plug the lines and connections at the compressor to prevent dirt and moisture from entering.

Remove or move the A/C compressor bracket, power steering pump, air pump, and any other components attached to the engine. Disconnect and plug all transmission and oil cooler lines.

SHOP TIPS--en removing the fasteners, pay close attention to their size and type. The brackets used to secure accessories use different size fasteners. Mark and organize the fasteners so their proper location can be easily identified later. It’s a good idea to store the fasteners in different containers, one for each system or section of the engine.

Electrical Connections--plug all electrical wires between the engine and the vehicle. Use masking tape as a label to identify all wires that are disconnected ( +++0 -9). Some engines have a crank shaft position sensor attached above the flywheel or flexplate. This sensor must be removed before separating the engine from the bell housing. Make sure the engine ground strap is disconnected, preferably at the engine.

Cooling System--Disconnect the heater inlet and out let hoses. Then disconnect the upper and lower radiator hoses. If the radiator is fitted with a fan shroud, carefully remove it along with the cooling fan. If the vehicle is equipped with an electric cooling fan, disconnect the wiring to the cooling fan. Then unbolt and remove the radiator mounting brackets and remove the radiator. Normally the electric cooling fan assembly and radiator can be removed as a unit.

+++0-12 A transverse engine support bar provides the necessary support when removing an engine from a FWD vehicle.

+++0-11 The exhaust system must be disconnected to remove the engine. Often this is the condition of the exhaust, so take care not to damage anything.

Miscellaneous Stuff--Disconnect the exhaust system; attempt to do this at the exhaust manifold. When disconnecting the exhaust system, make sure the wires connected to the exhaust sensors are disconnected before the system is moved. Remove any heat shields that may be in the way of moving or removing the exhaust system. Now carefully check under the hood to find and remove anything that may interfere with engine removal.

Removing the engine from a RWD vehicle is more straightforward than removing one from a FWD model, because there is typically easy access to the cables, wiring, and bell housing bolts. Engines in FWD cars can be more difficult to remove because large assemblies such as engine cradles, suspension components, brake components, splash shields, or other pieces may need to be disassembled or removed.

FWD Vehicles:

Before removing the engine, identify any special tool needs and precautions that are recommended by the manufacturer. Most often the engine in a FWD vehicle is removed through the bottom of the vehicle.

Special tools may be required to hold the transaxle and/or engine in place as it’s being disconnected from the vehicle. Always refer to the service manual before proceeding to remove the transaxle. You will waste much time and energy if you don’t check the manual first.

+++0-13 Use a large breaker bar to loosen the axle shaft hub nuts.

+++0-14 Pull the steering knuckle outward to allow the CV joint shaft to slide out of the hub.

+++0-15 Some engines are equipped with eye plates to which the hoist can be safely attached.

When the engine is removed through the bottom of the vehicle, use an engine cradle and dolly to sup port the engine. If the manufacturer recommends engine removal through the hood opening, use an engine hoist. Regardless of the method of removal, the engine and transaxle are usually removed as a unit. The transaxle can be separated from the engine once it has been lifted out of the vehicle.

Drive Axles-- Using a large breaker bar, loosen and remove the axle shaft hub nuts. It’s recommended that these nuts be loosened with the vehicle on the floor and the brakes applied.

Raise the vehicle so you can comfortably work under it. Then remove the wheel and tire assemblies from the front wheels. Tap the splined CV joint shaft with a soft-faced hammer to see if it’s loose. Most will come loose with a few taps. Many Ford FWD cars use an interference fit spline at the hub. You will need a special puller for this type of CV joint; the tool pushes the shaft out, and on installation pulls the shaft back into the hub.

Disconnect all suspension and steering parts that need to be removed according to the service manual.

Index the parts so wheel alignment will be close after reassembly. Normally the lower ball joint must be separated from the steering knuckle. The ball joint will either be bolted to the lower control arm or the ball joint will be held into the knuckle with a pinch bolt. Once the ball joint is loose, the control arm can be pulled down and the knuckle can be pushed out ward to allow the CV joint shaft to slide out of the hub.

The inboard joint can then either be pried out or will slide out. Some transaxles have retaining clips that must be removed before the inner joint can be removed. Others have a flange-type mounting. These must be unbolted to remove the shafts. In some cases, flange-mounted drive shafts may be left attached to the wheel and hub assembly and only unbolted at the transmission flange. The free end of the shafts should be supported and placed out of the way.

Pull the drive axles out of the transaxle. While removing the axles, make sure the brake lines and hoses are not stressed. Suspend them with wire to relieve the weight on the hoses and to keep them out of the way.

Transaxle Connections--Disconnect all electrical connectors and the speedometer cable at the transaxle. Then disconnect the shift linkage or cables and the clutch cable.

Starter--Now, remove the starter. The starter wiring may be left connected, or you can also completely remove the starter from the vehicle to get it totally out of the way. The starter should never be left to hang by the wires attached to it. The weight of the starter can damage the wires or, worse, break the wires and allow the starter to fall, possibly on you or someone else.

Always securely support the starter and position it out of the way after you have unbolted it from the engine.

Removing the Engine through the Hood Opening--Connect the engine sling or lifting chains to the engine. Use the lifting hooks on the engine or fasten the sling to the points given in the service manual. Connect the sling to the crane and raise the crane just enough to support the engine.

From under the vehicle, remove the cross-member. Then remove the mounting bolts for the engine at the engine and transmission mounts. With the transmission jack supporting the transmission, remove the transaxle mounts.

From under the hood, remove all remaining mounts. Raise the engine slightly to free it from the mounts. Then slowly raise the engine from the engine compartment. Guide the engine around all wires and hoses to make sure nothing gets damaged. Once the engine is cleared from the vehicle, prepare to separate it from the transaxle.

Removing the Engine from under the Vehicle--Position the engine cradle and dolly under the engine. Adjust the pegs of the cradle so they fit into the recesses on the bottom of the engine, and secure the engine.

Remove all engine and transmission mount bolts.

If required, remove the frame member from the vehicle. It may also be necessary to disconnect the steering gear from the frame. Double-check to ensure that all wires and hoses are disconnected from the engine.

With the transmission jack supporting the transmission, remove the transaxle mounts.

Slowly raise the vehicle, lifting it slightly away from the engine. As the vehicle is lifted, the engine remains on the cradle. During this process, continually check for interference with the engine and the body of the vehicle. Also watch for any wires and hoses that may still be attached to the engine. Once the vehicle is clear of the engine, prepare to separate the engine from the transaxle.

+++0-16 Mark the alignment of the rear U-joint and the pinion flange before removing the drive shaft.

+++0-17 Use a transmission jack to securely support the transmission before removing the motor mounts.

+++0-19 Once the engine is removed and is hanging on the engine hoist, lower it close to the floor so it can be safely moved to the work area.

+++0-18 If the engine is removed with its trans mission, remove the transmission mount and cross member.

+++0-20 A typical engine stand. SPX Service Solutions

RWD Vehicles:

The engine is removed through the hood opening with an engine hoist on most RWD vehicles. Refer to the service manual to determine the proper engine lift points. Attach a pulling sling or chain to the engine.

Some engines have eye plates for lifting. If they are not available, the sling must be bolted to the engine. The sling attaching bolts must be large enough to support the engine and must thread into the block a minimum of 1 1/2 times the bolt diameter.

If the transmission is being removed with the engine, position the hook of the engine hoist to the lifting chain so that the engine tips a little toward the transmission. Lift the engine slightly and check for any additional things behind and under the engine that should be disconnected.

Transmission If the engine and transmission must be separated before engine removal, remove all clutch (bell) housing bolts. If the vehicle has an automatic transmission, remove the torque converter mounting bolts.

If the transmission is being removed with the engine, place a drain pan under the transmission and drain the fluid from the transmission. Once the fluid is out, move the drain pan under the rear of the transmission. Use chalk to index the alignment of the rear U-joint and the pinion flange ( +++0-16). Then remove the drive shaft.

Disconnect all electrical connections and the speedometer cable at the transmission. Make sure you place these away from the transmission so they are not damaged during transmission removal or installation.

Disconnect and remove the transmission and clutch linkage. Disconnect the parts of the exhaust system that may get in the way. It’s best to do this by disconnecting as little as possible.

Use a transmission jack to securely support the transmission ( +++0-17) and unbolt the motor mounts. If the engine is removed with its transmission, the front of the engine must come straight up as the transmission moves away from the bottom of the vehicle. Remove the transmission mount and cross member ( +++0-18).

Removing the Engine--Center the boom of the crane (hoist) directly over the engine and raise the engine slightly. Make sure the engine is securely fastened to the chain and that nothing else is still attached to the engine. Continue raising the engine while pulling it forward. Make sure that the engine does not bind or damage anything in the engine compartment while doing this. When the engine is high enough to clear the front of the vehicle, roll the crane and engine away from the vehicle.

Lower the engine close to the floor so it can be transported to the desired location ( +++0-19). If the transmission was removed with the engine, remove the bell housing bolts and inspection plate bolts. On vehicles with an automatic transmission, also remove the torque converter-to-flexplate bolts.

Use a C-clamp or other brace to prevent the torque converter from falling. Also mark the location of the torque converter in relation to the flexplate.

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