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I have recently been given a '86 Buick Century with under 100,000 kilometers (I'm in Canada) from my father-in-law who seems to have driven it quite hard. I have discovered that it is using up the rad fluid, there is no noticeable leak underneath the rad when It has sit overnight, as well as when I start it up I usually get a fair bit of white/steamish smoke that has a slightly sweet smell to it (my first thought was antifreeze).

My first guess to this problem was my head gaskets starting to go, however from what I know about head gaskets is that when they are going you tend to have creamy or frothy substance in your rad fluid or oil, which both are clear of any such substance.

Is there anything else that could allow rad fluid to be used up in the engine?

As well It seems as the fluid changes have been neglected. Many people have said that a complete fluid change will cause more harm than good as the engine is used to the old fluids it has been using. Is there any good way to change these fluids? possibly mixing in a ratio of the old oil with new oil to get it used to better lubrication? Would a engine flush product from a local auto store be useful? or would it cause more harm? I have been told that mixing in a quart of tranny fluid for a quart of oil will help clean the engine slowly without causing it any damage. Is there a better way to gently clean/flush/change the fluids without causing any damage or future problems? (Oil/Tranny Fluid/Brake Fluid)  

that model was notorious for blown head gaskets...  the 3.0s also cracked a few heads...

it could also be leaky intake manifold gaskets... that dribble into an intake port...  

corrosion on intake manifold mating surfaces was also a sometimes problem...

pressure testing the cooling system....     doing a cylinder leak down test...  

one thing to watch on that model and earlier models of that design...   if you loose the a/c... blow out the fuseable link at the starter... the ac circuit takes an 18 gauge fusaable link...  but before you replace it...  with the battery disconnected.. rewrap the main harness between the ignition switch to a foot past the gas pedal mount...   some models have a hard to find short there...  putting in a solid wire causes the short to burn the entire harness usually resulting in a fire in the dash..   usually resulting in the loss of the car...

wisps of smoke from the steering column is the first sign of a problem...   it is the orange wire from the ignition switch that powers up the a/c relays over under the right hand dash...


if you end up pulling the heads... be sure to closely examine the exhaust manifolds...  they are usually welded tubes and have thermal cracks that can be welded..    when a lot of these cars came through the shop.. i had a head i would bolt the exhaust pipes to so i could weld them without fear of distortion...    i bolted them on tight.... every bolt... to the junk head... verified after welding ... a die grinder will open the holes up a tiny bit if it does distort...  

It is a 2.8l, I was kinda hoping it wasn't the head gaskets, or at the very least only the gaskets and not the heads themselves. what is the difficulty level of replacing the top end gaskets in these compared to newer cars. Last one i did was a 90 eagle talon.

Did not know about the shorting issue, but I will certainly keep and eye out for that.