My 2003 CL Type S with six speed suddenly does not produce any heat in the climate control system when set on 72 degrees; in fact, only when I turn the temp setting all the way up do I get a trace of heat. No coolant leaks, and the coolant level is fine. The system tries to compensate by turning up the blower when set on Auto, so the system 'knows" that it is not hot enough inside the car, but no heat is coming through. Any ideas or suggestions?
Joe

 

Could be a potential sign of the heater core going out. All other climate functions work okay?

 

Yes everything else works OK. How do I determine if it is the heater core or not?

 

Not sure if you've already tried this, but I had a similar problem happen. I just cranked up the heat to 90 and turned the fan speed way up, waited for it to get hot, then turn it back down to ~70 degrees and it seemed to do the trick. It should be noted that this happened on the first cold day of the year.

So it doesn't heat up at 72 even after you turn everyone on full?

 

some Q's

1. is this when the car is moving or stationary?

if it is when moving only, replace your t-stat

if it is both stationary and moving then you need to lube up your actuators with a special plastic safe grease. You will have to do some disassembly of the dash to do it