Valve Seals : Valve seals keep the engine oil from leaking into the intake and exhaust ports of the head through the intake and exhaust valves. These small seals are created to seal the valve stems and keep oil out and exhaust or intake air in. When valve seals fail, you will notice the vehicle smoking when it sits for a while and is started up. Extremely bad valve seals will cause oil to burn and the vehicle to have a lot of smoke from the tail pipe. Call Guy’s Automotive to get a quote on replacing your valve seals today.