Replacing an engine that’s broken down is one of the most expensive vehicle repairs an owner may be faced with.
While it may be tempting to junk or sell a car with a dead engine, many owners may not be in a financial position to ditch their ride. So, if you need to get back on the road and your engine is shot, how much does it cost to rebuild an engine? Let’s dig in to find out more.
How much does it cost to rebuild an engine?
In general, you can expect to pay anywhere from $2,400 to $4,700 for a rebuilt engine in most non-luxury domestic or imported brand vehicles. Expect simpler, smaller engines to be at the bottom end of the range. Larger or more complicated engines will be at the top end. Luxury brands or specialty engines in high-performance vehicles can easily top $10,000 or more.
The variation in cost comes down to the complexity of rebuilding the engine. During the rebuild process, the engine must be torn down, cleaned and reassembled with non-damaged parts. Simple four-cylinder engines from a brand like Honda cost less due to their durable, simple designs. They can be torn down and rebuilt in a short period of time. A complicated inline six-cylinder engine from a brand like BMW requires more work. Since shops charge by the hour for labor, this drives the price of the engine rebuild up.
What is a rebuilt engine?
A rebuilt engine has been completely disassembled and rebuilt with a combination of new and reconditioned parts.
In general, the engine block is reused when rebuilding an engine because it rarely suffers damage. Components such as heads, pistons and cylinders are often reused during the engine rebuild process. These components are machined and thoroughly cleaned so they look and function like new. Components like gaskets, hoses and other inexpensive components are almost always replaced during a rebuild.
Although a repair and a rebuild may seem similar, the two processes are different. Replacing components that are specifically damaged without turning attention to other undamaged components is considered a repair. In contrast, tearing an engine apart and replacing damaged components, as well as undamaged (but worn) components, is considered an engine rebuild.
Why do engines fail?
There are many reasons why an engine may fail, but the most common reason is exposure to excessive heat from poor maintenance, malfunctioning cooling systems or critical component failure.
In order to properly operate over a long period of time, engines must be properly lubricated and cooled. Lubrication cuts down on friction, which in turn keeps vital engine parts cool. If a vehicle is poorly maintained, the increased friction from old or dirty oil can cause heat. Once heat builds up, it can damage or warp critical components and cause the need for a rebuilt engine. Engines also have complicated cooling systems to help keep heat in check. A failure in the cooling system can lead to overheating and damage.
Engines also have timing belts or chains that precisely control the timing of valves and pistons in an engine. On some engine designs, a broken timing belt or chain can suddenly cause the pistons and the valves to come into contact with one another. Engines with this design–known as an interference engine–can suffer catastrophic damage and require a rebuild.
Signs that you may need a new engine
If you’re experiencing any of these problems, your vehicle’s engine may be in need of a rebuild:
Excessive oil consumption
Engines that are worn out may suffer from excessive oil consumption. As an engine ages, gaskets, seals and other components wear out. This means oil is either leaking completely out of the engine or it is being burned up during the combustion process. Some engines burn more oil than others, but in general, if your engine is burning up more than a quart every 1,000 miles, you have a serious problem.
Failing engines may produce a knocking sound that can be heard from outside your vehicle. This sound is produced by connecting rods in your engine that are in the wrong position due to a failing or failed engine bearing. The sound of knocking is from metal-on-metal contact that happens during the movement of the piston. Once metal starts hitting metal in an engine, the motor is most likely toast.
Smoke coming from tailpipe
There are many types of smoke from an exhaust pipe that could spell trouble for your motor. White smoke means that coolant is getting into the combustion chamber and burning. This indicates a worn seal or perhaps a blown head gasket.
Blue smoke is from oil getting into the combustion chamber, usually from a worn piston seal. Black smoke means that gasoline is entering the combustion chamber, again, usually from a worn seal or faulty injector. All of these symptoms indicate major problems that involve costly repairs or a complete engine rebuild.
If your engine suddenly feels like it’s short a few horsepower, this could mean your engine is doomed. It could also be a relatively minor issue. Issues with the ignition system, such as worn spark plugs, can be an easy and cheap fix. On the other hand, a loss of compression can be quite a bit more expensive to repair and could call for a full engine rebuild.
Decreased fuel economy
An engine that’s working hard due to failing components will suffer from poor fuel economy. Keep tabs on your miles per gallon, and if you notice a sudden drop in efficiency, it’s time to get it checked out.
Stalling or sputtering
Engines that stall or sputter are dangerous and should not be driven. Everything from a catastrophic loss of compression to a faulty fuel pump or malfunctioning electrical system could be the culprit.
Metal shavings in oil
If your mechanic tells you that they’ve discovered metal shavings in your oil during a routine oil change, your engine may need a rebuild. Metal shavings come from metal-on-metal contact, and their presence means that crucial parts of the engine are malfunctioning. In addition, metal shavings floating around in an engine are never a good thing and can cause damage themselves.
Check engine light is on
The check engine light helps drivers know that something is wrong with their engine. Yet only 36% of drivers actually investigate why their check engine light is on. Consider it an SOS from your vehicle. Ignoring it could mean that a relatively minor repair turns into a full engine rebuild.
Frequently Asked Questions
Is it cheaper to rebuild an engine or replace it?
It is cheaper to rebuild your vehicle’s engine than to replace it with another engine altogether. Rebuilding a motor reuses expensive parts and avoids the markup retailers place on replacement engines.
Is a rebuilt engine as good as new?
Yes, a rebuilt engine is as good as new. In some cases, a rebuilt engine can even be better than a new engine because updated, more robust components may be available for installation.
Is a rebuilt engine better than a used engine?
Yes, a rebuilt engine is better than a used engine. It’s nearly impossible to completely understand the previous history of a used engine, while a rebuilt engine is like starting from scratch.
Does a rebuilt engine need to be broken in?
Yes, a rebuilt engine needs to be broken in for maximum longevity and performance. It’s best to do a couple of medium- and full- acceleration runs within the first few hundred miles, but most mechanics will do this prior to handing you back the keys. In general, once you receive your car back, avoid long periods at idle and drive normally for at least 500 miles.