Can I Rebuild an Engine Without Removing It From the Car?

by Wesley Tucker
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dragster engine image by Robert Young from

An engine rebuild sounds like a big project and it can be depending on how for you want to go. Although pulling the engine out to rebuild it may be the easiest way to access the different parts, it can also be the most expensive. Pulling the engine means having an engine hoist, a stand and the means to move the engine around. Rebuilding the engine in the car is also possible but it just means working in a tighter space.

Engine Top

Start by draining all the fluids from the engine block and sealing off the fuel line. Then you can remove all the extraneous parts bolted to the engine: water pump, alternator, power accessory pumps, air conditioner compressor, air and oil filter, spark plug wires, rotor, distributor cap and everything screwed and bolted to the motor.

Once this is done you can remove the exhaust manifold, spark plugs and all the hoses and lines connected to the motor. After the manifold is removed you can take off the engine cover and begin work on the camshaft, lifters, valves and spring and fuel system (fuel injectors or carburetor depending on your car.) But you cannot pull the pistons yet.

Under the Engine

Remove the oil pan and drive shaft cover. Once the drive shaft is viewable, remove the piston rod connections. You can also remove the driveshaft through the engine block by removing the fasteners and cover plate in the back and the drive pulley for the serpentine belt in the front so it will slide out to the rear.

Once the piston rods are disconnected they can come up and out from the top of the engine.


The engine rebuild may mean either getting the parts back to factory specification or altering and improving performance with special parts. Rebuild the cams, camshaft, lifters, valves, valve spring, pistons and rings and the cylinder liners (some engines have steel engine blocks but cast-iron liners). You can also rebuild the driveshaft and piston rods.

One step to remember when doing a rebuild is to make sure every part is cleaned down to the bare metal and then thoroughly lubricated to specification when it is reinstalled. Don’t assume oil or grease will get to it later. That’s a great way to burn up a serious piece of machinery the first time you try to start it.


When rebuilding the engine, make sure you have plenty of room to lay out and organize all the parts. Try and keep similar components together. Be sure to rebuild the engine to factory tolerances and specifications. Just remember that if you have the time and energy to do your own engine rebuild to make sure you also have the financial resources to do the job right. The whole project can be completed in the engine bay without disconnecting the transmission and engine mounts to get the heavy block out of the car.

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