Buying a used engine can be a risky situation that will result in a much lighter wallet if you don’t know what to look for. Everyone is looking to make a buck in the import automotive business, and some are apt to lower themselves to shady practices to earn their dollar. By educating yourself you’ll be able to make informed decisions and ask the correct questions to keep from making a bad purchase. 

Know your Engine Specs
First, know what you’re looking for, and why. Part of making good purchase choices falls back on knowing what you want to use the car for. If you’re looking to make your ride to and from work more enjoyable and turn some heads in the process, then a JDM engine swap isn’t the best option because it won’t pass emissions standards. If you’re looking into racing, then you need to consider what type of racing and look into the specifications for engines allowed. SCCA tends to run stock parts and has a detailed list available on their website. If you’re into drifting, you’ll be looking for a rear-wheel drive or four-wheel drive option. 

Second, consider the source that you wish to purchase from. There are many different ways you can locate a used engine. An online auction, though alluring in this day of hectic schedules, can be one of the quickest ways to end up being scammed. If that’s the route you wish to take, then make sure you research the individual making the sale by reviewing sale ratings. Always email the seller to see if they’d be available by phone or email to answer questions. If they’re unwilling to answer your questions, then stay away from that seller. Keep in mind that if you are given a warranty, you’ll have to pay to ship a bad engine back to the seller, which can be expensive. 

A great way to find a used engine is through a local speed shop or auto shop that deals with import cars. Usually they’ll know if a seller is reputable, which sellers customers like to use for online purchases, and they can steer you to a local car club that specializes in import engines. They might even know of a customer that’s looking to sell the exact engine you’re looking for. 

If you’re considering buying an engine from a backyard source or a local junkyard you’ll be able to personally check for signs of wear and tear, such as a bad head gasket. Listening to the engine will prove that it runs decently, where if you’re unable to hear it run you’re at the mercy of the seller. One person’s “Sure, it runs great,” could be another person’s misery. 

Below are a series of steps you can follow to insure you get the most out of your used engine purchase. Most of the questions are geared to purchasing a used engine in person, which is the safest option. Seeing an engine up close and personal and listening to it run can give you more peace of mind on making a sound investment. If you’re purchasing from an online source, consider asking these questions so you can get an idea of what condition the engine is in. 
     
Used Engine Checklist
1. Before making a purchase, find out as much information as you can about the seller. Check out the Better Business Bureau to see if the business is reputable. There are a lot of online forums where other import car fans hang out and discuss engine swaps. Ask there about a company or even post to see what company they recommend. Check into the sales reviews of an online auction seller before considering a purchase. If it’s a private seller, stop by the local speed shop and see if they’ve heard anything about the seller. No one likes to blow upwards of a $1,000.00 for a bad engine, so protecting your wallet with a phone call or internet check is the first defense in getting the best deal.

2. When viewing an engine you’d like to purchase, open the radiator cap and look at the coolant—it should be clean. Coolant that is brown and nasty means the engine probably has a bad head gasket. Look for oil floating on the top of the coolant, as that’s another sign of a bad head gasket.

3. Pull the dipstick and check the oil. White milky foam on the dipstick could mean a bad head gasket.

4. Remove the oil fill cap from the valve cover. Stick your finger inside the valve cover and look at the residue left on your finger. White foamy film means the head gasket is bad. A sludge consistency means the oil may not have been changed enough, which could lead to other detrimental wear. Oil should be clean with no metallic particles.

5. Ask to see if there are any records for oil changes and other maintenance items. A well-maintained engine that has had oil changes at the proper times and other tuning specifications done at regular intervals will be more desirable.

6. Hear the engine run, if you can. It should run smoothly, no skipping, no smoke, no banging or other odd noises.

7. Check the spark plugs. Look at them closely for any signs of wear or damage. They should be light tan in color with no signs of corrosion or blackness. Black spark plugs or white ones with a crusty material are a sign of an engine problem that you don’t want to take on.

8. While the spark plugs are out, do a compression check on the engine.  You’ll want to see about 120 lbs. of pressure (some will be more or some will be less). If any of the cylinders vary by more than 10 lbs. over the other cylinders, then there’s a problem with the engine.

9. You can perform a Leak down test, which puts pressurized air into each cylinder to check for wear or potential problems. A local garage can perform this test for you for a fee if you’re unable to do so yourself. If the car is running and is computer controlled, consider hooking it up to a computer system to look for codes that will alert you to potential problems. Most auto garages can check an engine’s computer for you, for a fee, if you don’t have the equipment to do the job.

10. Ask if there is a warranty on the engine, especially if dealing with an online source. Ask what the policy is if the engine is installed by a private party, such as yourself, if you intend on doing the work. Some warranties are only covered if professionally installed, or they may have other limitations that you could void if using the wrong parts. Some junkyards and online sites only warranty the engine to run, and it may not be any better than what you already have. The length of the warranty starts the day they drop the engine off at your home, so if you’re doing the work yourself, make sure you can install the engine quickly and test it before your warranty runs out.