Got an 2007 TLS and the problem started yesterday. Im used to keeping my A/C on low and mid fan and today when I looked down my engine was almost on fire. no steam or smoke and when i turned off the A/C the car cooled down again. Not sure if its the compressor or radiator fluid.

 

Check our overflow reservoir, is it low or empty?

 

Most likely is that!.....or your thermostat

 

I dont why i didnt bother checking before I posted this but it was my fan. bad relay. cant find the facepalm smiley -__-