If the crush washers aren't sealing, tightening the bolts most likely will not help. There are different crush washers for the oil lines and the coolant lines so be careful which you use as the wrong ones will definitely leak. Good luck!
It's tricky to get to the bolts. You need an M8 triple square of just the right length, and skinny enough to pass between the hard feed and coolant lines. I used a combination of 4 adapters to make it work. I'm sure there's a $50 VAG tool just for the job.