Low Compression Engine: 7 Main Causes & How to Fix

Jerry Wilson
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Causes of Low Compression Engine

A low compression engine is an engine that fails the compression check. It could be an engine that is not yet running or an engine that is running but with a failing cylinder. Either way, a low compression engine is bad news because it fails to meet the minimum compression requirements.

Low compression engines tend to be caused by a variety of issues. While the list is long because there are so many potential causes, in most cases, the causes can be narrowed down to one of the following:

Bad fuel

Due to its high carbon content, bad fuel creates bad combustion in the engine. Because of that, the piston and cylinder are never able to reach the right compression ratio. Most cases of bad fuel are due to old fuel, which turns too acidic inside the tank.

Incorrect ignition timing

You could have a misadjusted ignition timing and the spark plug could be the wrong heat range. A false wiring can also cause this issue.

Incorrect compression

Because the cylinder head gasket is not perfectly aligned or has a pinhole or a crack, it could be leaking gas into the engine. Without the required compression, the engine is guaranteed not to work well.

Stale gasoline

How to Diagnose Low Compression

A Low Compression Engine is an engine that has symptoms of a compression issue. A compression problem often means there is a mechanical problem with the engine.

There are several symptoms of a possible low compression engine.

Engine Stalls when Coming to a Stop

There are a number of issues that can lead to an engine with low compression. Some of these are internal, while others (like a bad fuel pump) can be fixed with a simple service.

Cylinder compression is determined by the amount of pressure in the cylinder during the explosion that is needed to compress the air and fuel in the cylinder. The higher the compression in the engine, the more powerful it will be and it will be able to transmit more power to the wheels through the transmission.

Your Engine Needs ~13 Pounds of Compression Pressure

Under this amount of compression pressure your engine will not make full power and it will also have a hard time starting. The engine will have a rough idle and misfires. The engine is forced to work harder to go faster.

Loads of energy is lost because it needs more fuel to compensate for the low compression. This is why the engine feels low on power

How to Fix Low Compression Engine

A low compression engine is pretty unimaginable for some drivers. The thing they understand is that it will cost them more fuel and there will be more emissions. The fact is that the vehicle will be less powerful and that it may have a problem with the tire.

The first thing you should do is to check the condition of the tire. Usually, this is a quick diagnostic to check whether the issue is coming from the engine or from the tire. If the tire is not solid or worn out, it may be able to give you an issue.

Then check the inspection tags. This is also a quick action for you to take because the engine light is on in the dash board. Immediately, you should stop the vehicle and fix what is causing the problem.

When the engine light is on, it is consuming more fuel and it will cause more pollution. In many cities, this action will not be allowed because we are not allowed to drive with an engine light on. It will also indicate that we do not have the right kind of emission control with our vehicles.

For people who are living in busy cities, it is always better to fix your car as soon as the engine light comes on. Then the second option is to have an emission control test.

If the engine light on your vehicle is not fixed, you have to take your vehicle to a mechanic.


To conclude, there are a variety of things you can do to improve the health of your engine and increase the efficiency/compression of the motor.

The long term benefits mentioned above are a good enough incentive for you to spend some time on finding the best solution to get your engine running smoothly.

Don’t forget, you also have other ways to monitor the health of your motor, and they are the power and sound of the engine.

We all know what it’s like to have a better car that runs quietly and smoothly.

We also all know what it’s like to own a car that’s giving you troubles and is costing you a fortune to repair.

Aside from the obvious repair and maintenance, you can take some preventative steps as well.

You can choose the most cost-effective way to get out of paying hefty engine repair bills.


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