Valve Stem Seals

HOW TO DETECT THE VALVE STEM SEALS FAILURE

To check the valve stem seals serviceability, start the vehicle engine, warm it up and gradually increase the revs to 4,000 per minute. Ask an assistant to watch the exhaust pipe. If blue-gray smoke starts coming out of the tailpipe after you have sharply released the accelerator pedal, this means that the valve stem seals are worn out. At a service station you can check the CH2 level in the exhaust gas with the help of special equipment: if its content exceeds the norm, it means that oil gets into the exhaust system, which may also show that the components have to be replaced.