Five reason why you car could have low compression

Technical

Sep 11th, 2019

Five reason why you car could have low compression

What is car engine compression, and why is it important?

Compression is the force behind the functionality of any engine

Engine compression results when the air and fuel are compressed in a small volume and mixed in the engine cylinder. It is the ability to measure the gases that are confined in the cylinder. 

It is essential to always check the compression pressure by doing a compression test. Whenever the engine is not running well, or doesn't produce enough power to move the car, it is likely to be because of low compression. 

Different parts are responsible for maintaining the compression ratio and fault in any of them results in low compression pressure. These are;

 1.     Cylinders 

Low compression sometimes results from fuel washed cylinders. In the case too much fuel enters the motor, it washes off oil from the cylinder walls. The oil will act as a seal between pistons and cylinders, and this results in fuel washed cylinders.

 2.     Pistons

Pistons get the most impact from the engine being fired because they are closest to the engine. Over time, this will result in the pistons being worn out and getting damaged or torn. 

Faulty pistons will enable air pressure release from the cylinders, hence resulting in low pressure.

 3.     Valves

Leaking valves are often the cause of low compression, and they should be closed tightly to ensure there is no leakage.

4.     Timing belt

Timing belt not only controls the position of the pistons, but it also helps direct which valves should open and close. The timing belt should be in good order always to ensure that the car runs without hitches. A worn-out timing belt results in low compression pressure.

 5.     Head gasket

The seal that is placed between the engine block and cylinder head is called the head gasket; this ensures that gas and oil do not mix. The head gasket wears out with time, and can sometimes crack creating airspace. This airspace provides an outlet for pressure, resulting in low compression pressure.

 Low motor compression is a common occurrence that is easily avoided by ensuring your vehicle is booked in for its periodic servicing, the recommended service dates are located in your owners handbook!


Do NOT miss these services, or else you could be fitting the bill for a supply and fit for another engine! Costs involved in fixing a car with low compression sometimes can be 10x more than a replacement motor!