Hello. I have just had to install a new head on my mitsubishi exspress van. 2 litre carby model 4g63. I have torqued down the head bolts to specifications in the manual 1 - down to 80nm. 2- loosen all off completely 3- tighten to 20nm 4- tighten a quarter of a turn 5- tighten a further quarter of a turn. All done in sequence. I have noticed small oil leaks from both sides at front of head. What is wrong? Can I torque down another 5 millimetres to fix this? It is a standard gasket.