VALVE STEM TOP HAT SEAL A PLUS

As an engine wears the clearance between the valve stem and guide increases; as this gets beyond tolerances the car will tend to smoke under decelleration (when you take your foot off the gas). Good valve stem seals will allow for greater wear before the smoke becomes intolerable. These were the latest model seal in an improved material with little springs in the neck to help create a better seal. For the best available see LJQ101160 made in Dupont Viton material as used by Rover on the MPI engine.