The relatively low mileage of your car means that these regular maintenance issues are worth tackling. To rid your system of algae (formed because of water resting in the tank), clean the filter in the tank (check archives on this forum for procedures) and use the additive described above. Replace the timing chain and tensioner soon. 5 - 6 degrees of stretch could mean an impending chain break - bad news. The improved performance and peace of mind will make it worth while. Clean out the banjo bolt and attached tube, adjust ALDA and disconnect the EGR. The car you will be driving on the other side of these tasks will be a great thing to have. Best of luck and please let us know how it goes.