Changing a car engine at home is one of the most difficult tasks you will face as a home mechanic. Replacing the engine requires different approaches for every year, make and model, therefore it’s important to refer to the service manual specific to your vehicle while taking on such a big project. While the process may be vary from vehicle to vehicle, the basic elements of the engine swap are fairly universal and this can be considered as the basic outline of the procedure.

1. Remove The Hood

Most projects done “under the hood” can be undertaken without removing the hood. Removing the engine from your vehicle however, is not one of them. The hood could possibily interfere with your ability to access the connections or bolts and could cause problems while lifting the engine out of the engine bay.

2. Drain All Fluids From The Engine

An engine has a number of different fluids for regular use and all of it has to be drained out prior to removing the engine. It’s best to start with the engine oil, which should be drained through the oil drain plug in the oil pan, then move on to the coolant, which can be drained through the radiator petcock (it’s should be noted that there will still be coolant left throughout the system as you disconnect coolant lines). The washer fluid reservoir is usually attached to the body of the vehicle, and can therefore be left alone.

3. Disconnect The Intake, Exhaust And Coolant Lines

The intake draws air into the engine. It will have the appearance similar to that of a pipe or tube that is traveling from the air filter to the throttle body. You will need to disconnect the pipe from the throttle body, remove all the fasteners holding the intake in place and remove it from the engine bay. Remove the radiator as well, if necessary. If not, simply disconnect the coolant lines that are connecting the radiator to the old engine.

4. Disconnect The Wiring

Depending on your vehicle, there is a lot of wiring possibilities that you might have to address while conducting the engine swap. Latest models have more wirings and sensors compared to the older ones and should be dealt with more care so as not to damage the connectors as you pull them apart. Since it is so varied, you should also refer to the service manual specific to your vehicle’s year, make and model to ensure you disconnect all of the appropriate connections.

5. Unbolt The Engine From The Transmission

The transmission will be behind or to the side of the engine depending upon how the engine is mounted in the vehicle’s engine bay. The bell housing of the transmission will generally be at the back of the engine, or opposite to it where you will find the serpentine or drive belt. You should remove all of the bolts that pass through the bell housing of the transmission and into the engine block and then place a transmission jack below the transmission to support its weight after it is no longer connected to the engine.

6. Disconnect The Motor Mount Bolts

The engine in most vehicles are connected by three motor mounts and a fourth motor will act as the transmission mount. These motor mounts are usually made up of steel and rubber, so as to absorb engine vibration. It is usually a single bolt that is passing through the mount to secure the engine. Use a wrench on one end of the motor mount bolt to hold it in place while you use another wrench to loosen and remove the nut from the other side. If you decide to use a cherry picker to lift the engine out of the engine bay, make sure to use your vehicle’s service manual to find the points to bolt the chain to the engine without causing any damage.

7. Either Raise Or Lower The Engine From The Engine Bay

 Depending on the design of your car, it may be easier to leave the engine where it is and raise the vehicle itself over it or raise the engine out of the engine bay using a cherry picker. If you are using a professional lift, raising the vehicle above the engine is fairly easy, but home mechanics might have trouble using this method, therefore, using a cherry picker might be best.