The rubber plug that seals access to the camshaft chain tensioner release mechanism is prone to shrinking, becoming brittle and leaking oil. This is just one of many areas of the V-12 engine that are prone to oil leakage.
This project involves replacing the rubber plug with an aluminum, "O-ring equipped plug (photographed below), manufactured by Ron Kelnhofer. The tensioner plug is constructed of clear anodized 6061 aluminum with a Viton "O" ring for sealing. This is an outstanding product. Cost is less than $20.00 US.
Ron also manufactures aluminum half-moon seals. The installation of these half-moon seals are covered in a separate link of this website.
First, the original rubber plug must be removed. It is not unusual for this plug to literally fall apart during the removal process. Some, or all may fall into the engine cavity. Don't worry, it will not harm anything. Using a small thin screwdriver, carefully pry the old plug out. (yellow arrow photograph below).
Pictured below are the old and new plugs. Note broken off "ear" of old plug. The new plug is extremely well designed and manufactured.
The redesigned aluminum plug is retained in the engine cavity with a steel ball whose movement is controlled by a 3/32" Allen screw. This screw must be backed off to allow the steel ball to retract before the plug can be installed in the engine opening.
Once the steel ball is retracted, I recommend liberally coating the plug and "O" ring with engine oil prior to assembly.
Clean opening before installation. New plug installs with firm pressure. Tighten Allen screw to lock plug in place. (green arrows photographs below).
Aluminum tensioner plug installation complete. This plug will never harden, shrink or leak.
