oil pressure 86 944

i have a weird problem with my 944. i have had for some time an oil leak in the oil cooler region but have been putting off the repair until winter when it is parked. recently while driving the oil pressure will drop almost to 0 and the temperature will shoot up at the same time . while this is happening i can smell oil fumes and see smoke out the back. i am sure that these 2 things are tied in together but i would sure appreciate some insight into this as to cause and effect before i tear it apart . i should also mention that it will just as quickly cleasr itself up and everything returns to normal, but when the levels are checked they are always down a bit after this happens. sam