'86 Skylark overheats after 15 minutes of driving. Any suggestions? Oil and water are okay.

36% means only that much of it's life is left.

If you vehicle is low on oil it will say check oil. To do so you need to open the hood and use the dipstick to do so.

Also if your ol life is only 36% that usually means you have driven 6000 miles since your last oil change............ I suggest every 3000 miles.

Okay William,here's a guide on how to replace.http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?fromSearchPage=true&pageId=0900c1528025f58f&partName=Water+Pump&partId=0900c1528025f58f Here's the part and price.http://www.autozone.com/autozone/parts/1996-Buick-Skylark/Water-Pump/_/N-j4u85Z8ii0v

try replacing the thermostat. it's easy and cheap to fix. I find it hard to believe the water evaporates after 5 minutes though. you may have a bad freeze plug and your loosing all your water or a blown head gasket. check the oil and make sure it isn't milky looking or obvious signs of water in the oil

i just had changed the oil in my wifes 2.7 2000 260,000 mile concord.
i got a very unhappy phone call about oil light on and over heating .
shop wanted $750 to fix . i drove it home no light till about 15 minutes into drive. checked oil it didn't even regester .waited a few minutes oil was back. ended up being the pcv valve was pluged and line to it had
rotted off . it was holding the oil in the valve cover and causing it to leak
around plugs and burn oil . cost of fix $20. i used a radiator bypass hose and a new pcv valve . works great .still burns quart of oil every 1,000 miles because of milage .i hope this info will be useful to you.

Well first off, since you have replaced many parts, perhaps you have air in the system. Also check the oil to see if it looks like chocolate milk or is extremely high (indicating a blown head gasket).
While system is cold, add coolant to the radiator (if applicable) and the coolant tank. Then start the vehicle and turn the heater on high heat - full blast. Let run for 15 minutes or until the engine begins to overheat or the coolant tank become empty. Let the vehicle cool down (30 minutes) then repeat until it coolant level doesn't drop or engine doesn't overheat.
Now go for a test drive for about 10 - 15 miles make sure to take hills and highway/freeway. Let vehicle cool down and recheck coolant tank and radiator. If level has gone down then something is wrong. Perhaps the thermostat is in backwards.

you have a 1.8 liter turbo engine correct? it is the water pump that is driven by the timing belt. 100% positive this is correct i have replaced countless water pumps for this reason. the reason it overheats while driving is becuase the splines on the water pumps plastic impeller are gone and it is just freewheeling on the pump shaft. at idle the pump spins slow enough to get the impeller to turn. very very very very common. replace water pump timing belt and tensioner.

Sounds like you either have a blown head gasket, cracked head, craked cylinder wall or if equipped a faulty oil cooler. You can try to replace the head gasket and hope that fixes the problem.

Check to see if there is water in the oil...If there is water in the oil then it could have a head gasket problem...Excessive exhaust backpressure because of a clogged catalytic converter could also cause overheating..Also check belt tension and condition. A loose belt that slips may prevent the water pump from circulating coolant fast enough and/or the fan from turning fast for proper cooling...Another thing it could be is a faulty Water pump -- Any wobble in the pump shaft or seepage would call for replacement. In some instances, a pump can cause an engine to overheat if the impeller vanes are badly eroded due to corrosion or if the impeller has come loose from the shaft. The wrong pump may also cause an engine to overheat. Some engines with serpentine drive belts require a special water pump that turns in the opposite direction of those used on the same engine with ordinary V-belts... Also check the Fan -- With mechanical fans, most overheating problems are caused by a faulty fan clutch, though a missing fan shroud can reduce the fan's cooling effectiveness by as much as 50% (depending on the fan's distance from the radiator) which may be enough to cause the engine to overheat in hot weather or when working hard.

change water pump

you may try replacing the computer,i had the same problem with my buick last year. a new computer solved the problem.