What causes piston rings to break?

Answer 1

the rings kind of seal in the sides of the piston with the cylinder wall. When a compression test is done the air is escaping between the piston and the cylinder where the good ring would normally seal. If you are getting low compression it is more likely the valves

Answer 2

The main reason piston rings break is because they have been allowed to run for too long without adequate lubrication as they slide up and down the cylinders.

If the engine oil has not been changed regularly according to the manufacturer's service guidelines - along with removal of the old oil filter and replacement by a new one - then, over a time period starting from about two missed oil changes, the increasingly more dirty oil will lose more and more of its "lubricity".

The lack of lubricity causes excess friction between the various moving parts of the engine, particularly between the very hot piston rings and the cylinders.

In addition to reduced lubricity, small particles of oxidised (burnt) oil and other debris - most of which would normally be removed every time the oil filter gets changed - will soon begin to build-up into ever- larger "clumps". These reduce the flow rate of the oil and can eventually clog-up the oil channels, thus making the lack of lubrication get worse and worse, until something breaks, such as one or more piston rings and/or one or more of the crankshaft or camshaft bearings.

Another answer

There can be many causes for a piston ring to freeze up and break, the most common would be oil not getting to the piston this is caused by no oil in the engine or using wrong weight of oil on engine. Other causes can be overheating of the engine that can be caused by broken head gaskets letting water into the oil and mixing, or the engine overheating by no water flowing in the engine this is caused by radiator leak or a frozen thermostat. Other issues could be from someone rebuilding the engine and not using correct rings or incorrectly installing them.

Answer 3

There can be many causes for a piston ring to freeze up and break, the most common would be oil not getting to the piston this is caused by no oil in the engine or using wrong weight of oil on engine. Other causes can be overheating of the engine that can be caused by broken head gaskets letting watter into the oil and mixing, or the engine overheating by no water flowing in the engine this is caused by radiator leak or a frozen thermostat. Other issues could be from someone rebuilding the engine and not using correct rings or incorrectly installing them.