Engine Replacement – Engine Choices – Before And After Checks

Engine Replacement - Engine Choices - Before And After Checks
Engine Replacement - Engine Choices - Before And After Checks

So, engine replacement, is one of the more difficult tasks, a mechanic may ever face.

Because, engine replacement, requires different approaches for every year, make and model.

Above all, engine replacement is, much more complicated than simply, pulling the old engine and bolting up a fresh one. But, if your vehicle is in relatively good shape, engine replacement makes more sense, than replacing the vehicle.

Firstly, because engine replacement can be challenging, I would suggest getting a service manual, specific to your vehicle.

Most importantly, knowing what caused the engine to fail, is the first step in any repair.

Engine Replacement
Engine Replacement

So, anytime you’re replacing an engine, you need to work methodically, to get it right the first time.

Also, don’t be afraid to go to an expert for help. Consequently, it will save you a lot of time, money and headaches in the long run.

If Your Old Engine Had 150,000 Miles On It, So Do Other Parts Like:

  • Power steering
  • Air conditioner
  • Cooling system
  • Charging system
  • Starting system
  • Transmission
  • Sensors and relays

So, odds are they all need to be replaced or at least tested. Because, if you ignore these basic tips, there’s no guarantee you won’t be facing, constant repair bills.

While the process may be different from vehicle to vehicle, some elements of an engine swap, are fairly universal.

Engine Swap
Engine Swap

Some Basic Tips That Should Be Done Or Checked, Before Engine Replacement:

  • Check the motor mounts. Replace them if they are worn, loose or cracked.
  • Check the condition of the clutch or torque converter, transmission, CV joints, U-joints, etc., and make any repairs as needed.
  • Some items on the engine such as, manifolds brackets, accessories, spark plugs, oil filters, sensors, etc. Will probably be easier to install on the engine, while it is still out of the vehicle.
  • Preassemble as much as you can, then finish the rest of the items, once the engine is in place.
  • Install new oxygen sensor(s). Also, highly recommended, on high-mileage engines. Consequently, to guarantee proper fuel feedback control, good fuel economy and emissions compliance.
  • Install new belts and hoses (also, check automatic tensioners and idler pulleys and replace as needed).
  • Install a new coolant temperature sensor and thermostat. Also, highly recommended, to reduce the risk of overheating and possible engine damage.
  • Install new spark plugs, plug wires, distributor cap and rotor (if equipped).
  • Scan the computer for fault codes, fix any problems as needed, and clear the code memory.
  • Check for any (PCM) flash updates, that may be available from the (OEM). Then, re-flash the computer as needed.
  • Check for any engine related technical service bulletins, that are out on the vehicle. And, make any upgrades or changes as recommended.

Engine Replacement Options Include:

  • Used Engines
  • Rebuilt Engines
  • Remanufactured Engines
  • New “Crate” Engine

Used Engines

So, a used engine is one that was likely, pulled out a vehicle that was wrecked. And, had damage to another one of its mechanical systems, that ended up sending the vehicle to the junkyard. However, just because it’s been in a vehicle wreck, doesn’t mean it’s no good. Used engines are often a good choice and they’re often more affordable, compared to a brand new one.

Used Engines

The engine most likely, doesn’t have a lot of miles on it. And, didn’t need to have any parts replaced. So, this is often the cheapest method, of replacing an engine, if one can be found.

Repaired, Rebuilt Engines

A rebuilt engine, like a used engine, was pulled out of a vehicle. But, it has had some parts replaced. It was likely disassembled, cleaned and put back together. Along, with any parts that needed to be updated and new gaskets throughout.

Rebuilt Engines

When done properly, a rebuilt engine can last, for hundreds of thousands of miles.

Remanufactured Engines

So, the highest quality option for engine replacement in your car, truck or SUV, involves a remanufactured engine. This means that an engine, was returned to, factory condition.

Remanufactured Engines

Machining of the block, crank and heads, along with all other parts, to restore their specifications. Then, that the engine operates as if it was, brand new. And, sometimes comes, with an added warranty. But, will likely last longer, than a used or rebuilt engine. But, they will cost more up front.

New “Crate” Engine

A new engine uses all new parts. Including an, engine block, crankshaft, cylinder heads, connecting rods, camshaft, pistons, and valves.

New “Crate” Engine

Because of this, a new engine will cost, considerably more than a reman engine.

So, as you can see there are many options available to you. And, each has their own features and benefits. Therefore, do your research and make the right choice.

Pre-Installation Inspection Tips, For Any Engine Replacement:

  • Inspect the entire engine thoroughly. If there is an issue, you want to find out, before you have it installed in the vehicle.
  • Match the long-block with your old one. Make sure they are, exactly the same.
  • After you have the old engine out, set it next to the used engine. Then, identify which components, need to switched over.
  • If you find damaged components in your inspection (timing cover, oil pan, etc.). Then, swap the components with your old engine.
  • Don’t install a replacement salvage engine, with damaged parts. This may cause the used engine, to fail prematurely.
  • Inspect all the timing components on the engine. For instance, if miles are over factory specification for a timing belt or chain, replace timing components.
  • Best practice is to always, replace the timing belt. It’s generally inexpensive to do, when the engine is already out of the vehicle.
  • Inspect all gaskets for bolt on accessories. And, replace any gaskets, that look brittle or are leaking. Finally, change over any bolt on accessories needed, off your old engine.


So, if your engine is nearing the end of its useful life. You may wonder whether to, rebuild or replace it. Consequently, the warranty available, could play a role, in what type of engine you choose.

Remember, you’re going to need to pay for more than just the engine itself. Furthermore, even if you have the skills required for engine replacement. The process itself, can cost several hundred dollars.

Thank You !