BMW V8 Valve Stem Seal Replacement

Worn valve stem seals are a very common issue on BMW’s 4.4 liter and 4.8 liter V8’s found in many X55-Series, and 7-Series BMW’s. When valve stem seals wear out, engine oil will leak from the cylinder head, past the valves, and into the intake and exhaust ports, culminating in increased oil consumption as the oil is either burned in the combustion chamber or in the hot exhaust pipe.

“What are the symptoms of worn valve stem seals?”

The main symptom to watch out for is smoke coming out of the exhaust, and possibly a burning oil smell. You may also notice reduced engine performance, depending on the severity of the problem.

(Click images for larger version.)

Our customer brought this X5 (pictured above) to us to diagnose the cause of oil smoke coming from the exhaust and sure enough, the problem was worn out valve stem seals. Fortunately for him, we are equipped with specialized tools that allow us to perform this repair without having to remove the cylinder head, allowing us to provide a huge cost savings to the customer. If you were to have these valve stem seals replaced by the dealership, the typical procedure involves removing the entire cylinder head, requiring many more hours in labor and resulting in nearly twice the cost of what we are able to charge, not to mention the lengthier down-time of the vehicle.