How to Remove Engine Pistons

by Justin Chacos

Overhauling an engine is a rewarding, fun, intensive, and difficult task, all rolled into one. Hundreds or even thousands of individual parts must work in harmony for smooth engine operation. When deciding to overhaul an engine, you should fist determine the scope of the project. Will you overhaul the engine to restore it to factory or performance condition, or just to repair a particular problem? Either way, you must remove the engine pistons during a proper rebuild operation.

Clean the engine compartment with a degreaser designed for engine cleaning. This is a messy task and may be regulated by local law. A clean engine compartment reduces the risk of foreign material damaging the engine or components and makes removing engine components easier.

Drain the vehicle's oil, coolant and fuel systems. Depressurize the fuel lines. Disconnect the negative battery cable.

Take off the hood and remove the radiator fan.

Remove the engine mounted accessories, including the air delivery system, throttle body, distributor, alternator, air conditioner compressor (without disconnecting the refrigerant lines), power steering pump, connecting hoses, hardware, lines, cables and wires. Mark each component by making a flag out of masking tape and labeling it with an indelible marker. Be especially thorough with wires and electrical connectors.

Remove the intake plenum and manifold. Use a gasket scraper or razor blade to remove the old intake manifold gaskets. Remove the fuel injectors and label them for correct reinstallation.

Connect the engine to an engine sling. Connection varies by both engine and sling manufacturer.

Remove the shifter if the vehicle has a manual transmission. Disconnect the torque converter plate, lower the drive shaft, disconnect the transfer case if the vehicle is four-wheel drive and remove the transmission mount bolts. With the engine sling taught, remove the engine mount bolts.

Lift the engine and transmission from the vehicle and set on a clean, supporting work surface.

Take off the cylinder heads and remove the old gasket. Clean the heads with shop rags and inspect them for cracks or other abnormalities.

Mark each piston face with correctional fluid correlating with its position in the engine. This is typically done from the front of the engine to the rear, but any manner works that will cue proper placement during reinstallation.

Clean the top of the cylinder bores thoroughly. If there is a significant cone shape to the cylinder, smooth it with a cylinder ridge reamer.

Remove the oil pan. You should be able to see the crankshaft and connecting rod caps. Remove the two bolts holding each connecting rod cap then work the cap free from the bearing and crankshaft journal.

Remove the pistons and connecting rods from the top of the engine through the cylinder bores.

Tip

  • check Keep the working area clean. Clean the removed parts in a different section of the garage than where they are being neatly stored.

Warning

  • close Do not allow the transmission to strike the vehicle windshield as it is lifted from the vehicle.

Items you will need

About the Author

Justin Chacos is a professional mechanic with experience on all vehicle types, from cars to boats to airplanes. He has been writing since 2006 and has been published in multiple maintenance manuals and journals. He holds a Master of Science from the University of Arkansas.

Photo Credits

  • photo_camera piston de scooter image by Vetea TOOMARU from Fotolia.com