i bought a 94 sc400 with 191k on it.
its been great for the past two months but now my heat is only coming out luke warm.
if i run the car for 30min it gets close to normal heat wise.
the temp gauge gets right to the middle though as it should in about ten min or less.
its full of coolant.
any ideas on what the lack of heat is?
the car as you know warms up pretty quick,at least mine did untill know.
also i noticed something strange.
i keep my engine so clean you could eat off it,the other day when i opened the hood there where
some stains that almost looked like road salt residue.
they did put salt on the roads but could that get inside the hood?
also the pan under the radiator seems to have some kind of oil on it.
i checked all my fluids and there full,very strange indeed.
something is not right,if its a leak i dont know what,or where.
any ideas?
thanks.

 

coolant leak, top off the coolant to the very top. monitor the level over the next week.

 

Check your heater control valve. It's located on the right side fire wall in the engine bay. Have a friend look at it when you turn on the heat and a/c if the little arm does not rotate it's inop.

 

wont a stuck closed thermostat also caus a no heat condition?