I have a 2001 Lexus ES 300- 120,000 miles. For over a year, I have been having problems with it over heating sporadically. It only happens when it is 90+ degrees outside-I live in Texas, so this happens alot. It always happens the same way. The air conditioning in on and the air starts getting warm. This goes on until I am idling at a light or in traffic. I then hear a loud clunking noise–gauge is still showing my engine is not hot. The clunking stops. Then all of a sudden my gauge jumps to extremely hot–goes as high as it can. I turn the air off and try and get out of my idling situation. Steam starts coming out of my engine off to the right. I pull over as soon as a can. I let the car cool and then I can drive it again with no problem. This is very intermittent. My auto shop has done the following and has now thrown in the towel and wants me to go to the dealer. They cannot make it happen for them. Since it has gotten cooler after Sept, it has not happened again. We are now in January and nothing has happened for several months. Can you give me a clue on what this can be? Summer will be here before we know it and I will be afraid to drive again. I have tried everything. My dad thinks there is something in the air conditioning that is the cause it because it only happens when the air is on.
Some of this was Maintenance Items.
9/12/2015 Replace Radiator Cap, Flushed Coolant, Replaced Lower Radiator Bushings
11/21/2015 Replace Water Pump Timing Kit, Replaced Timing Belt, New Coolant
11/21/2015 Replaced Valve Cover Gasket
11/21 15 Replaced Spark Plugs
11/21/15 Replaced Fuel Press Regulator
5/17/16 Replace accessory relay 1 ea wells
7/7/16 Replace Radiator Fan Assembly
7/7/16 Replace Fan Clutch
9/6/2016 Replaced Thermostat
It has overheated since replacing the thermostat.