started losing a bitta power over weekend on my e320 cdi 05 reg . took it to mechanic an he noticed 2 injectors were leaking air . he started to take bolts off rocker cover but realised the injectors were not goin to come out without special tool so referred me to merc specialist . on putting bolts back he somehow managed to damage thread going into the head . now gotta have thread re done b4 new bolt can go back in . dramas dramas . any body ever experinced this situation an also any idea how much new rocker cover is an two new injectors ?