I think the normal case is that the tensioner wears and oil leaks between the piston and cylinder so doesn't provide proper tension. You will notice it takes longer for chain noise to fade on start up and if ignored, you hit a bump while driving and the chain is slack enough to slap the guides and they shatter. If that happens it will sound like you are using the engine to polish rocks.

If chain is loose typically bank one cams will spring advanced when the lobes get past center. Only a couple will be lined up with the sensor notch on the reluctor wheel so you could possibly get a particular cylinder error but typical error is cam too advanced bank one.

__________________
2011 E70 • N55 (me)
2012 E70 • N63 (wife)