Piston rings: common defects and their signs

1. Loss of mobility due to carbon formation.
   • Engine operation worsens.
   • Smoke appears from the engine crankcase ventilation hose.
   • Motor oil ingress in the air filter.
   • Excessive smoke appears from the exhaust pipe.
   • The engine operates with failures.
2. Wear-out.
   • Motor oil consumption increases.
   • Black smoke comes from the exhaust pipe.
   • Fuel consumption increases.
   • The spark plugs get oiled, deposit is formed on them.
   • The engine loses power and acceleration capability.
   • Oil stains are visible on the sealing elements of the engine.

How to repair or replace piston rings?

Operational lifetime of the piston rings is individual for every car, on average, their lifetime is 150 000 – 300 000 kilometres. Quality of used motor oil, air filter, fuel and car operation conditions influence components wear rate.

Possibility of piston rings restoration depends on a defect, which caused its inoperability. In case of carbon formation, chemical cleaning with the help of special compounds may be effective.

If the piston rings are damaged or worn, their immediate replacement is necessary. Specialists recommend to replace the engine gaskets, and motor oil and the air filter simultaneously with the piston rings kit.

Full demounting of the engine, the algorithm of which depends on the car model, is necessary to perform replacement. Then, defective piston rings should be removed. Ring ends in the lock area are pulled to the sides, until the part comes out from the piston groove. Before installation of a new piston rings kit, their gap should be measured – it should comply with requirements of vehicle technical documentation. Condition of the cylinder walls or sleeve should be checked in a mandatory manner. Also, during rings replacement, it is important to take into account their mutual disposition, type and direction of the ring. Manufacturers mark mounting direction of the spare part to facilitate installation.

It is highly difficult to perform installation of new piston rings on the car having no special skills and equipment. For this we strongly encourage you to employ services of a car maintenance station.