Your vehicle's engine should last for nearly 200,000 miles. Of course, that assumes you're diligent about maintaining it properly throughout its life. You need to swap out the spark plugs, air filter, and change the oil periodically. You also need to replace the timing belt and change the coolant at regular intervals. Most people neglect to do these things and as a result, their engines fail long before the 200,000 mile marker. When this happens, their choices are limited to buying a new vehicle or replacing the failed assembly.

In this article, we'll concentrate on buying a replacement. There are a few options available, including having the assembly rebuilt or swapping it for a remanufactured or crate engine. I'll describe each choice as well as what you can expect from the mechanic after installation.

Remanufactured Versus Rebuilt

Before making the decision to replace your engine, you should have your mechanic determine whether your current assembly can be rebuilt. If it can, that will be the least expensive route. Keep in mind, however, that the extent of the repairs needed to get your car back on the road may be excessive given the cost of replacing the assembly.

The type of repairs needed will also play a role. A blown head gasket or worn valve guides can be easily, and inexpensively, replaced. A cracked block, on the other hand, requires a significant amount of time and labor. That translates into a much larger repair bill.

If your engine cannot be rebuilt, it must be replaced. You'll have three options: used, remanufactured, or new. Used assemblies can be bought at salvage yards. Unless your budget is limited, avoid this option (OEM-certified used assemblies excluded). There's no way to know for certain whether there are individual components on the verge of failure. Plus, even if the salvage yard offers a warranty, it usually does not cover the price of installation.

Remanufactured assemblies are cheaper than new ones and far less risky an investment than buying from a salvage yard. They are usually dismantled so the individual parts can be inspected and cleaned. Components that are worn are replaced. Remans are typically backed by warranties that cover the parts and installation labor.

Meeting Emissions Standards

A lot of people who buy remanufactured or used engines never consider that the assemblies may fail to meet emissions standards. When they take their vehicles in for a routine smog check, they're surprised to learn they're out of compliance.

This happens when the replacement assembly does not perfectly match the original. For example, it may not line up or connect with the oxygen sensors. It may have special pistons that don't match and hence, cause emissions control problems. If you're planning to purchase a remanufactured or used unit, make sure it is compatible with everything else under your car's hood.

Straight From The Crate

Buying a crate engine is the best option if you can afford to do so. It's a brand new assembly, so there is no risk that individual parts are already worn. Moreover, you can customize the replacement with more torque and horsepower. Crate assemblies are more expensive than remans, of course. But, given the low risk of owning a brand new engine, the investment might make sense.

The Test Drive: What The Technician Tests

Once the replacement engine has been installed, your mechanic should take your vehicle for a test drive. This is critical in order to make sure the assembly has been installed correctly. The technician will listen for a knocking sound in the cylinders; he'll listen for misfires and backfires; he'll test your cruise control, heater, and air conditioner; he'll make certain your vehicle is idling properly when at a full stop. Once he's certain the installation is problem-free, he'll turn your car over to you.

To be sure, replacing your engine is expensive. However, doing so is usually a less costly alternative than buying a new vehicle.