cat..good heads up. reminded me of a diagram showing the
chain tensioners being loaded by two "pressure valves" (left and right).
http://www.bmwmcchattanooga.com/show...ssembly=191929
The interesting thing is only one of them has a internal spring preload. They
both appear to be what I would call "hydraulic valves" as they appear
to have oil drain holes in them. I would think if the spring were
compromised your valve timing on start up would be off and
maybe some knocking until the "tensioners" were brought up to pressure.
Just a guess.