How to Break in a New or Rebuilt Engine

Engine break-in refers to a set of protective steps aimed at helping the moving parts of your engine settle in and make it last for a long time. A proper procedure for engine break-in is critical because it might save your engine and bank account.

You may have heard that engine break-in is a myth that most service centres use to earn extra money or doesn’t apply to modern vehicles. The second myth might be slightly true because, unlike older vehicles, modern cars have engines built with more robust materials and run better fluids; therefore, they are ready to be used out of the box.

However, most experts and manufacturers agree that engine break-in is an excellent idea and recommend that car owners be cautious during the “break-in period” or the first thousand miles. Being careful during this period will guarantee the long-term performance and health of your engine.

Read on to learn how you can properly break in a new or rebuilt car engine.

Should You Break in a New Car?

When you buy a new car, you might be very tempted to know what it’s capable of. However, pushing your engine too hard during the first 1,000 miles could be detrimental in the long run. It is crucial to break in an engine for maximum power before crossing the 1,000 miles mark.

Breaking in an engine ensures minimum wear and that the oil flows evenly and smoothly through all moving parts. Additionally, it gives the piston rings adequate time to sit correctly and provides sufficient time for the transmission and engine to adjust.

The time required to break in an engine differs by each manufacturer. However, most recommend avoiding high revolutions per minute (RPMs) during the first 1,000 to 1,500 miles.

Advantages of Breaking in an Engine

There are several reasons why breaking in the engine of your new car is a good idea. Here are some of them:

Improved Long-Term Engine Health

Breaking in an engine within the first 1,000 miles helps in the smooth flowing of oil through the system and ensures that moving parts are working efficiently. These two reasons play a significant role in ensuring optimum engine health in the long term.

Improved Fuel Economy

New engines hardly ever reach peak efficiency until after several thousand miles. Therefore, driving within the manufacturer’s break-in rules will help in maintaining excellent fuel economy.

Better Engine Performance

Breaking in an engine helps limit friction and ensures that parts are well-balanced and working together efficiently; therefore, ensuring better performance and delivery.

Techniques for Breaking in a New Car

Here are some techniques that will help you break in a new car and ensure optimal engine health:

Avoid Short Trips

Short trips aren’t ideal for brand new cars because they do not give the engine adequate time to warm up. Cold engines usually work harder; hence, they put a lot of strain on the oil delivery cycle. It’s advisable to drive your new car for longer trips that will allow your engine to warm up enough.

On the other hand, you should drive gently if your car has been working hard during a long journey. For instance, if you’ve driven on the motorway for a long distance, drive it gently before through town before reaching your destination to allow the engine to cool instead of coming to a hard stop.

Do Not Overload Your Vehicle

It would help if you didn’t overload your vehicle by exceeding the car’s passenger capacity or payload limits. More load means more weight; therefore, your vehicle will have to rev higher and work harder to get moving.

Additionally, it would help if you didn’t tow heavy loads because towing puts added strain on engines in normal driving conditions and can damage new vehicles that haven’t been broken in.

Do Not Push the Engine Too Hard

It’s not advisable to push the engine to the red line before hitting the first 1,000 miles. Pushing the engine too hard can strain the cylinders and piston rings and worsen any manufacturing imperfections.

Experts recommend that 4,000 RPM is safe during the first 1,000 miles. After 1,000 miles, you can progressively increase the RPM without any negative repercussions.

Avoid Flooring the Accelerator

Flooring the accelerator of your new car can put a lot of strain on the piston rings, engine oil, and cylinders. Additionally, aggressive acceleration before the engine warms up could be harmful despite the number of miles you have covered.

It would help if you accelerated gently during the first 1,000 miles and walk through the gears quickly before RPM can build too high. This technique ensures smooth engine performance.

Change Gear at a Low RPM

Breaking in a new car allows adequate time for the transmission and engine to adjust to one another. Therefore, changing gear at a low RPM avoids unnecessary wear and tear. This technique can also help with fuel economy.

Adjust Your Driving Style

It would help if you weren’t thinking of the engine only when breaking in a new car. It would help if you also thought of the brakes, tires, and suspension because they need time to bed in too. Vehicles cannot handle much when straight out of the factory floor; therefore, it’s best to be cautious to ensure maximum safety.

During the first 200 miles, tires may not offer an adequate grip that you except because they’re covered with a lubricant applied during the manufacturing process. It takes several miles to ensure that the oil has fully worn off.

Brakes also require adequate time to adjust because the disc and pads need to start working together to develop friction spots that ensure smooth and effortless stopping performance.

Do Rebuilt Car Engines Really Need to Be Broken In?

Breaking in a rebuilt car engine is critical, and if it’s not done completely or correctly, the engine is most likely to perform poorly, consume oil or smoke. It’s worth noting that these symptoms are irreversible over time.

Low load and idle time on a freshly rebuilt engine can result in “glazing” of the cylinder walls and prevent piston rings from sealing correctly. “Glazing” refers to a condition where fuel deposits and hard oil build up on the cylinder walls, preventing the rings from sealing correctly. When glazing forms, it can be challenging or impossible to remove it without disassembling the engine.

What to Do After an Engine Rebuild

Rebuilders know what to do after an engine overhaul and often have their techniques for engine break-in. Some of them include:

  • Use the heaviest trailer and steepest hill you can find and drive up to it.
  • Drive to the speed limit very fast, and then while still in gear, let off the throttle and let it coast to the stop-repeat if need be.

You can apply the following tips if you break in a rebuilt diesel engine:

  • Alternately heat and cool the piston rings under varying RPMs. Ensure that you operate the engine under moderate loads at varying RPMs for around 10 or 15 hours.
  • Put a heavy working load on the engine at almost 15 hours, and get the engine hot. Ensure the coolant temperatures rise and keep the revs up.
  • After 15 hours of heavy working load, start operating the engine under moderate loads again. Always ensure that the engine gets up to average operating temperatures.

Does Rebuilding an Engine Make It Like New?

A rebuilt engine refers to the one used for most of its useful lifespan and has been completely overhauled to extend its lifespan. Such an engine has its internal components refinished, repaired, or replaced with new parts. It’s worth noting that a rebuilt engine is not a new engine; however, if an engine is rebuilt correctly, it can extend the lifespan of your car considerably.

There is a difference between a rebuilt and a remanufactured engine. A remanufactured engine is one with all new parts and has been completely overhauled to high or original factory specifications.

Do I Need Special Break-in Oil for a Rebuilt Engine?

Break-in oil is not the same as regular motor oil. Regular motor oil is designed to prevent wear, while break-in oil is supposed to allow the rings to wear down the peaks on the cylinder wall to form a good seal.

New vehicles do not need break-in oil; however, people using a new crate engine or a rebuilt engine should use break-in oil. It’s essential to follow the rebuilder’s instructions when using break-in oil.

Check this too: How to Remove a Broken Sparkplug

Having a new car is exciting, especially if it’s your first. However, following the break-in guidelines will allow your vehicle to survive for a long time and could help you save money. Additionally, your car will reward you by offering uncompromised performance and reliable service.