When an engine develops a serious fault, replacing the entire vehicle or even replacing the complete engine is not always the only solution.
Depending on the condition of the engine and the cause of the failure, engine repair, engine rebuilding or engine reconditioning may provide a practical way to restore reliability and performance.
At Approved Engines, our experienced team provides specialist engine repair, rebuilding and reconditioning services. The most important first step is identifying what has failed and why before deciding on the right course of action.
What Is the Difference Between Engine Repair, Rebuilding and Reconditioning?
Although the terms are sometimes used interchangeably, they generally describe different levels of engine work.
Engine Repair
An engine repair normally focuses on fixing a specific fault or replacing individual damaged components.
This may be suitable when the problem is limited to one area and the rest of the engine remains in serviceable condition.
Engine Rebuild
An engine rebuild involves dismantling the engine so internal components can be cleaned, inspected and measured.
Worn or damaged parts can then be repaired, machined or replaced before the engine is carefully reassembled.
Engine Reconditioning
Engine reconditioning involves restoring usable engine components and replacing parts that no longer meet the required condition or tolerances.
Depending on the engine, this can include cleaning, inspection, machining and replacement of worn components.
The right option depends on the type of engine, the symptoms, the cause of failure and the extent of internal damage.
What Are the Signs That an Engine May Need Repair or Rebuilding?
Engine problems do not always result in an immediate breakdown. Some faults develop gradually and give warning signs beforehand.
Symptoms worth investigating include:
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Knocking, tapping or unusual engine noises
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Persistent overheating
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Excessive exhaust smoke
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Loss of engine power
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Poor acceleration
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Low oil pressure
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Increased oil consumption
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Coolant loss
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Oil or coolant contamination
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Engine misfires
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Difficulty starting
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Poor compression
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Warning lights that repeatedly return
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Metal particles in the engine oil
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A seized or non-running engine
One symptom can have several possible causes, so these warning signs do not automatically mean the engine requires a full rebuild.
Accurate diagnosis is essential before major work begins.
When Can an Engine Be Repaired Instead of Rebuilt?
An engine repair may be possible when the fault is confined to particular components and the main internal parts of the engine remain usable.
The exact repair will depend on the diagnosis.
Problems involving gaskets, cylinder heads, timing components and other engine parts may sometimes be addressed without rebuilding the complete engine.
Early diagnosis can make an important difference.
For example, continuing to run an engine that is overheating, suffering from poor lubrication or producing abnormal mechanical noises can cause further internal damage.
If your engine starts behaving differently, investigating the problem early may help prevent a smaller fault from becoming a much larger repair.
Learn more about our engine repair, rebuild and reconditioning services.
What Happens During an Engine Rebuild?
Every engine and failure is different, but a professional rebuild generally follows a structured process.
1. Diagnosis
Before rebuilding an engine, the cause of the problem needs to be understood.
Finding the failed component is only part of the diagnosis. It is also important to investigate why it failed, because rebuilding an engine without addressing the underlying cause could lead to another failure.
2. Engine Strip-Down
Where a rebuild is required, the engine is dismantled so its internal components can be properly inspected.
This allows technicians to identify wear or damage that would not necessarily be visible from outside the engine.
3. Cleaning and Inspection
Components are thoroughly cleaned before being examined for problems such as:
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Excessive wear
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Scoring
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Cracking
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Distortion
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Bore damage
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Bearing damage
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Damaged sealing surfaces
Measurements can then be taken to determine which components remain serviceable.
4. Machining, Repair or Replacement
The findings from the inspection determine what happens next.
Depending on the engine and its condition, work may involve components such as:
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Cylinder heads
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Engine blocks
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Pistons
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Piston rings
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Crankshafts
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Main bearings
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Big-end bearings
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Gaskets and seals
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Related internal components
Approved Engines' engine rebuilding services include work on cylinder heads, engine blocks and bottom-end assemblies.
Cylinder Head Reconditioning
The cylinder head is a critical part of an engine and can be affected by overheating, gasket failure and other mechanical problems.
Depending on its condition, cylinder-head reconditioning may include:
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Cleaning and degreasing
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Pressure testing
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Skimming
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Valve cleaning
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Valve lapping
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Valve polishing
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Inspection for damage
Proper assessment helps establish whether a cylinder head can be reused or requires further repair.
Engine Block and Bottom-End Rebuilding
The lower section of an engine includes important components such as the crankshaft, bearings, pistons and connecting assemblies.
During bottom-end rebuilding, components can be cleaned, measured and checked for wear.
Where necessary, Approved Engines can replace main bearings and big-end bearings and check piston-ring gaps against the appropriate specifications.
Engine-block damage does not necessarily mean the block must always be discarded.
In suitable cases, damaged bores may be repaired using liners, while bore machining may be an option depending on the application and condition of the block.
Repair vs Rebuild vs Replacement Engine
There is no single answer that applies to every damaged engine.
Engine Repair May Be Best When:
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The fault is relatively localised
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Major internal engine components remain usable
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The cause can be identified and corrected
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A complete rebuild is unnecessary
Engine Rebuilding or Reconditioning May Be Best When:
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There is significant internal wear
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Several components need attention
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Major engine components can still be restored
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Keeping the existing engine is a sensible option
Engine Replacement May Be Best When:
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The existing engine has suffered extensive damage
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Repairing or rebuilding is uneconomical
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Important components cannot be restored
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A suitable replacement engine provides the better solution
Approved Engines also provides an engine supply and fitting service, so replacement can be considered where rebuilding the existing engine is not the best route.
How Much Does an Engine Rebuild Cost?
There is no accurate fixed price that applies to every engine rebuild.
Costs vary because two engines showing similar symptoms can have very different levels of internal damage.
Factors that can affect the cost include:
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Vehicle make and model
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Engine type and specification
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Extent of internal damage
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Components requiring replacement
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Machining required
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Cylinder-head condition
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Engine-block condition
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Cause of the original failure
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Labour required
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Parts availability
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Removal and refitting requirements
For this reason, diagnosis and inspection provide a much better basis for estimating the cost than a generic advertised price.
Is It Worth Rebuilding an Engine?
An engine rebuild can be worthwhile when the engine is suitable for restoration and repairing the vehicle makes sense overall.
Factors worth considering include:
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The condition of the rest of the vehicle
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The severity of the engine damage
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Availability of replacement engines
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The expected repair cost
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How long you intend to keep the vehicle
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The value of the vehicle
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Whether the vehicle is used commercially
For business vehicles, downtime and the cost of replacing the complete vehicle may also influence the decision.
The best approach is to assess the engine first and compare the available options.
Why Choose Approved Engines?
Approved Engines has more than 20 years of experience supplying, rebuilding and reconditioning engines.
Our specialist engine services include:
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Engine fault diagnosis
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Engine repairs
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Complete engine rebuilds
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Engine reconditioning
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Cylinder-head reconditioning
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Engine block repairs
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Bottom-end rebuilding
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Engine supply and fitting
We use quality components and take a diagnosis-led approach so the work carried out is based on the condition and requirements of the individual engine.
If you are outside our immediate area or want to check service availability, visit our Areas We Cover page.
Frequently Asked Questions About Engine Repair and Rebuilding
Can a damaged engine always be rebuilt?
No. Whether an engine can be rebuilt depends on the extent and type of damage. Some engines are suitable for rebuilding, while severe block, crankshaft or other internal damage may make replacement the more practical option.
What is the difference between an engine rebuild and engine repair?
An engine repair normally addresses a particular fault or component. An engine rebuild involves dismantling the engine, inspecting its internal parts and repairing or replacing components as required before reassembly.
What is engine reconditioning?
Engine reconditioning involves restoring usable engine components through processes such as cleaning, inspection, machining and refurbishment while replacing components that are excessively worn or damaged.
How do I know if my engine needs rebuilding?
Symptoms can include knocking noises, excessive smoke, poor compression, high oil consumption, overheating, low oil pressure and substantial loss of performance. Diagnosis is required because these symptoms can also be caused by faults that do not require a complete rebuild.
Is it cheaper to rebuild or replace an engine?
It depends on the engine and the extent of the damage. A rebuild may be economical when the main components can be restored, while replacement may make more sense where the existing engine has suffered extensive damage.
How long does an engine rebuild take?
Timescales depend on the engine, damage discovered during strip-down, parts availability and any machining work required. An accurate timescale normally becomes clearer after the engine has been assessed.
What parts are replaced during an engine rebuild?
There is no universal list. Components are inspected and measured, with worn or damaged items repaired or replaced as required. These may include bearings, piston rings, gaskets, seals and other internal engine components.
Can a damaged engine block be repaired?
In some cases, yes. Depending on the type and location of the damage, engine-block repairs may include fitting liners or machining damaged bores. The block must be inspected to determine whether repair is suitable.
Can Approved Engines supply and fit a replacement engine?
Yes. In addition to engine repairs and rebuilding, Approved Engines provides engine supply and fitting services where replacing the existing engine is the more appropriate option.
Need Help With an Engine Problem?
If your vehicle is overheating, losing power, producing excessive smoke, making unusual engine noises or has suffered a major engine failure, the first step is establishing exactly what has gone wrong.
Rather than assuming the engine automatically needs replacing, a proper assessment can determine whether repair, rebuilding, reconditioning or replacement offers the most appropriate solution.
Explore our engine repair, rebuild and reconditioning services or contact Approved Engines to discuss your engine.
