Chain Tensioner Service Interval
 

My '81 911SC had the stock tensioners rebuilt back in 1995 with 50K miles on the car. Car currently has approx. 65K miles. Is it time for another rebuild (or installation of Carrera-style tensioners)?

Thanks.

no - Porsche considered a belt and rejected that (quieter) solution b/c it would have to be replaced every 15k or so (given the technology in belts back then)

your chains ~~should~~ last as long as your rod bolts or valve guides and will et you know when they are ready to be liberated from the engine by making a sound like a ghost dragging a... ah.. chain... across a metal garbage can

Check if you have tensioner collars on the tensioners. Tensioners, either hydraulic or oil fed, either are working or failed.
Bruce