85 6.9 guidence
 

Im fairly new to diesels. I just got my first one picked it up pretty cheap. Its a 85 f250 6.9 in it. it runs good. But it has some bugs that need to get worked out. First the battries drain overnite, there used and i wanted to get an idea of what could be drainin them before i get new ones. Also it smokes blue and white when first started and then continue after fairly warmed up. Wonderin if it just needs an oil change (which im planin on doin once the weather is fair) or what it could be. Oh and lastly what is the best oil for these rigs?

A bad diode in the alternator can kill batteries pretty quick. If you replace the batteries, make sure the new ones have at least 1000CA each.

The smoking could be due to your timing being off, a bad injector, stuck rings. We will need more details on that to further diagnose. Changing the oil could help if it is old and thin though.

As far as oil, get 15-40 and pick a brand. You may notice that your truck consumes more of one brand than another. Change it and keep track of how much you have to add before it is due again, then try another brand if you aren't satisfied. Everyone gets different results with the same oil so find what works best for you.

well i changed the oil and oil filter and it seems to be smokin less but i havent let it warm up all the way due to im almost outta diesel. but i might have found the prob with the battries. i testin stuff with the voltage tester and i found one of the horns was still live so keep ya updated when i get the plates for the truck