hi there i own a 1988 toyota p/u v6 when i am at idle my heat cools down .when i speed up it heats up again.. could someone help me here i cant figure this one out...Also when i first start the truck in the morning it runs ruff for 5 seconds then idles fine?? thank u

there are a few things that you should check, first, your fan. second your thermostat, make sure it is the correct degree that toyta recomends, and finally you need to check your radiator cap to ensure pressure is being held in the cooling system. check all hoses and all clamps, also make sure that your not clowng white smoke when you rev it up, this is a sign of a blow head gastket which the six cylinders are nitorious for.