I have a 95 4runner that is my daily buy my brothers truck is acting funny. It runs and drives great 170k miles but it uses oil and under load it will blow white smoke. I know the seals are bad on oil pan and there is oil on manual transmission. I didn't know if it could be rings or if it could be blowing oil out of some place and getting on exhaust. He tried pulling the 89 toyota out of a mud hole and it had white smoke come out from under his truck.

 

Sounds like rings are going out. Check and make sure your pcv isn't bad tho but more than likely rings.