For many car owners, engine failure is one of the most expensive failures to deal with. A brand-new engine can cost thousands of dollars ,and even a remanufactured engine could cost anywhere from 10 to 20 percent of the cost of a new vehicle. With that in mind, looking for a used engine sounds like a better deal.

However, it pays to be careful when looking for a used engine. The following offers several helpful tips that can aid you in finding the best used engine available while avoiding common and potentially expensive pitfalls.

What to Check

After finding the right engine for your vehicle, you'll want to make sure it's in good condition. After all, your "new" engine won't be any good if it fails within the first few hundred or thousand miles of service. Here are a few crucial areas to check before you purchase a used engine:

• Exterior appearance – Grab a reference image of the engine you're looking for and compare it to the engine you've found. This will give you a chance to spot any missing or damaged components. If you see a little rust, don't worry; an engine that's been exposed to the elements for a short period may develop a little surface rust, but heavy amounts of rust and corrosion should be a red flag for any buyer.
• Engine oil – Take a look at the engine oil's appearance. If it contains metal flakes, shows signs of coolant/oil mixing or appears sludge-like, avoid the engine at all costs.
• Crankshaft/piston movement – The next step is to make sure the engine isn't locked up by rust or physical changes in the cylinder or piston. You can do this by turning the crankshaft by hand. Simply attach a socket wrench onto the crankshaft pulley nut and turn the pulley in a clockwise direction. The crankshaft and pistons should turn freely with moderate effort – an engine that turns too easily or feels locked up should be avoided.
• Spark plugs – The state of the spark plugs can say a lot about the engine's health. On a healthy engine, the spark plugs should appear relatively clean or, at the worst, slightly oily with the electrode showing little wear and a light tan or gray appearance.
• Coolant – Check the coolant passages for signs of clean green or orange engine coolant. Be wary of engines that used ordinary tap water, since it typically hints at previous overheating problems.

Mileage Matters

Another thing you'll want to know about any used engine is the amount of miles it's accrued during its previous life. Despite not being the final word in describing the engine's overall condition, it can tell you whether you're dealing with one that's come from a relative creampuff of a vehicle or if it's seen more than its fair share of road.

It's a good idea to buy from a vendor who's taken the time to record the vehicle's mileage before harvesting its engine. Otherwise, you'll only be left with the vendor's estimate of mileage.

After the Purchase

Once you've bought your used engine, you'll want to make sure it remains ready for the road for many miles to come. Here are a few preventative pre-installation measures you can take to give your engine a longer, healthier life under the hood:

• Consider changing the water pump prior to installing the engine. An unexpected water pump failure could defeat the whole purpose of finding a used engine, so it's better to be safe than sorry. Besides, installing a water pump is much easier with the engine out of its bay.
• If the engine came with its original belts, now is the time to add a fresh set for safety's sake. Old belts can easily be removed from their pulleys while the engine is outside of the vehicle.
• Depending on the engine's age and mileage, you should also consider having the timing chain or belt inspected and, if necessary, replaced. Not only does this give you peace of mind, but it'll also prevent your used engine from turning into a glorified paperweight in short order.
• Don't forget to change the spark plugs and the oil filter before the installation.

With these tips on hand, you'll be able to save up to thousands of dollars on the cost of a new or refurbished engine by going used without getting burned. For more information, contact a local used auto parts dealer.