[SRT356/911]

This is the 3rd time that I have had head nuts come loose. 2nd on a 3L and 1st on a 3.2.

The 3.2 was built by a renowned engine builder, so I need to think that it happens. When I told him I was getting oil seepage he knew right off the head nuts were coming loose.

The other 2 were steel studs in 930 case. No dilivar studs.

The studs are not coming out of the case. The nuts are just coming loose.

All studs were wire brushed clean and oiled along with the nuts and washers.

All studs were torqued to 26 ft lbs.

How common is this? Why is it happening?

Just re-torque them and go down the road? How often should they be checked?