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Remanufactured Engine Basics

New engine or new car?

No engine, despite what often-repeated tall tales and infomercials would have us believe, runs forever. Even the best of engines will eventually wear out. The engine under your hood is comprised of a great number of precisely machined moving parts that work together under brutal conditions to harness the power of internal combustion. If your engine's get-up-and-go has got up and went, or folks call the fire department because of the cloud of smoke emitting from your old bucket, it may be time to consider a remanufactured replacement engine.

You Make the Call

A trusty older or high-mileage vehicle can often be given a lease on life by way of an engine transplant. The key point to remember before you make the decision to replace the engine is that the rest of the vehicle's systems, and the vehicle itself, must be in good working condition. Bolting up a fresh engine to a malfunctioning fuel or cooling system can amount to a very expensive and time-consuming mistake. On the other hand, a remanufactured engine may be just the ticket if you've recently invested in a replacement transmission or major system components only to have the engine die.

The Long and Short

Remanufactured engines tend to come in two flavors: long, and short. A "long block" is a complete engine assembly from top to bottom. A "short block" consists of just the bottom end of the engine. The block and rotating assembly of crankshaft, connecting rods and pistons make up the bottom end. Which version you choose depends on which part of your engine fails, or how worn out it is overall. If you recently replaced a cylinder head or heads, and your engine starts burning oil through the piston rings, kicks a connecting rod, or burns a bearing, you may only need a short block. In most cases the long block is the most cost-effective choice.

Core Support

Long block or short you will need to strip the old engine of its parts and trade in the worn out guts for the core deposit. Keep in mind that if your engine has suffered severe damage, such as a cracked or windowed block, it will be useless as a core and this cost will have to be added into the total cost involved. The oil pan, timing cover, oil pump pickup and other associated engine parts must be removed from the old engine and re-used. If any of the parts are in dire condition, replacement costs should be added into the decision-making process. A long block usually comes as an engine with an engine gasket kit, and a new oil pump—that's it!

Shade-tree Shady

Remember that "rebuilt" is a very relative term. Don't trust slip-shod methods when it comes to engine rebuilding. A properly rebuilt engine is completely remanufactured by professional machinists. Blocks are bored, honed and decked to exacting tolerances. New pistons, rings and bearings are installed. All tolerances are checked and re-checked. The machines and equipment required to properly remanufacture engines are not something everybody has lying around, and the skills required to run them are not easily learned. A correctly rebuilt engine is as good or better than new.

Break-In Right

Engine removal and replacement is a job that requires experience and facility. While most remanufactured engines come with a warranty, proper installation and break-in procedures must be followed or the warranty will be void. All reused components must be thoroughly cleaned and checked. The engine oiling system must be properly primed before starting. Many variables such as pre-ignition, a fuel lean-out or a loss in oil pressure can spell the end of an engine before it gets a chance to begin. If proper installation and break-in procedures are followed, a remanufactured engine should provide years of service and is a good choice to keep an otherwise sound vehicle moving down the road.