What can cause my recently bought used car engine to blow?

This blog post will answer the question, ‘What can cause my recently bought used car engine to blow?’, and cover topics like what is a blown engine, the symptoms of a blown engine, the causes that lead to a blown engine, and how to avoid a blown engine.

What can cause my recently bought used car engine to blow?

These are the following reasons that can lead to a recently bought used car engine blowing:

  • An overheating engine
  • Improper lubrication
  • Broken or worn-out timing chains
  • Formation of holes in the car engine block
  • Poor or lack of maintenance
  • Ignorance of problems by the previous user of the car
  • Poor maintenance by the previous user

What is a blown engine?

An engine that has suffered severe damage and needs replacement or rebuilding is what we refer to as a blown engine. Blown engines signify a major problem that has occurred inside the engine.

A blown engine primarily occurs when a valve forms a hole at the top of a piston and the oil that has been pressurized escapes and leaks out. The connecting rods that act as the link between pistons and the crankshaft have also been known to form a hole thus damaging the engine.

Symptoms of a blown engine

These are some of the following symptoms that resemble a potentially blown engine.

Blue exhaust smoke

This is a definitive sign of a blown engine as it indicates that the natural engine oil is getting added into the combustion chamber, thus resulting in the emission of blue smoke from the tailpipe of the car.

White exhaust smoke

White exhaust smoke when emitted out of the tailpipe of the car indicates that either water or the engine coolant is entering the combustion chamber.

White smoke from the exhaust is different from the normal smoke as it is denser and it stays suspended in the air for a while. 

Presence of coolant in the engine

The coolant and the engine oil of a car are sealed away in separate compartments, and in no way whatsoever must they mix together. In case they do, it can cause a serious issue and might cause a blown engine.

Rattling sound from the car

Internal engine noises while the car is in motion and the engine is running is a strong indicator of a blown engine. The main cause behind this issue can be either broken or worn-out engine bearings.

Poor performance and loss of mileage

Subsequent wear and tear cause a loss of mileage and poor performance. However, if the power and mileage drop drastically and all of a sudden, it might indicate a blown engine.

Engine shakes in a violent matter

If the car engine starts shaking in a violent manner, it can be a strong sign of a blown engine. The main cause behind this can be defective spark plugs, however, they are cheap to replace.

Causes of a blown engine

These are the following causes that give rise to a blown car engine.


An overheating engine can cause most of its crucial components to fail. It mainly happens due to a coolant leakage from the radiator or a wrong thermostat. A defective water pump or a cooling fan can also cause this problem.

Lubrication not done properly

Lubrication is a necessity for all the moving engine parts and a lack of the same can be caused due to a high mileage car or rigorous wear and tear in the parts.

Broken timing chain

The car’s timing is generally maintained by connecting the crankshaft to the camshaft, and this is done with the help of a timing chain. A broken timing chain can inflict severe damage to the car valves in the cylinder head.

Hole in the Engine block

A hole in the engine block is a serious issue and must be attended to immediately. This is more common in high-performance vehicles and is mainly caused by the connecting rods breaking a hole into the engine block.

Poor or lack of maintenance 

A lack of maintenance can cause slime or sludge to build up in the oil galleries and other critical parts of the engine. This can prevent proper lubrication if the oil and oil filters are not changed regularly.

How to avoid a blown engine?

These are some remedies in case of a blown engine.

Regular checking of engine oil

Engine oil is the main life source of the engine and should be checked and replaced regularly as per the requirements. Regular engine oil checking becomes even more important in the case of an older car.

Engine tuning

If the car engine acts sluggishly and in an abnormal manner, engine tuning becomes all the more important. It mainly involves changing the air filters and replacing defective spark plugs if any.

Replacing worn-out timing belts

A timing belt is essential for maintaining the optimum timing for the car and any squeaking noises coming out of the engine indicate the need to replace the timing belt.

Avoid engine overheating

It is important to prevent a car engine from overheating as it may cause other essential parts to function improperly. It is, therefore, important to regularly check engine coolant levels as all the combustion inside generates a large amount of heat.

Research shows some common engine problems according to the car brands.


This blog post addressed the question, ‘What can cause my recently bought used car engine to blow?’.

We understood what it means to have a blown engine and came across the symptoms to help us identify a blown car engine. Furthermore, the various causes and remedies for a blown car engine have also been discussed. Please feel free to comment on the content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): What can cause my recently bought used car engine to blow?

Will your car start if the engine is blown?

A blown car engine will result in the car not starting. Even if it does, weird noises like rattling or squeaking can be heard along with jerky or shaky movements of the vehicle while running.

Can a blown engine be fixed?

It totally depends on the degree of damage done, if it is minimal, the parts can be replaced. However, severe damage will require a complete engine overhaul, costing a lot of money.

How much is a car engine?

Engines belonging to used cars can cost somewhere between 3000-4000$ while new car engines can cost between 4000-6000$.