This is a very old thread, but it may still be of interest to some.......
It appears that oil mist and oil thrown about in the crankcase can work its way up into the oil pan bolt threads, and result in the bolts loosening.
While locktite may work for some time, I would not trust it as a long term fix.
One suggestion that may assist the locktite solution would be to place fresh copper washers under the bolt heads. That should form an effective additional seal to prevent oil from reaching the threads.
Cheers, Tony.
