Vandal

Excuse my ignorance, but what do you mean by coil packs? Ignition coils, got it.

Excuse my ignorance, but what do you mean by coil packs?

Hi All Another HO2S sensor query. My check engine code indicates the back heated oxygen sensor is reading faulty. Does anyone know how to measure the voltage from somewhere in the engine compartment? Also, if I wanted to remove the sensor it looks as if the sensor connector is located under the carpet under the front seats. Is this correct? Can you pull the connectors out through the access port on the bottom of the car? Thanks dave

I have a 1990 LS400 that developed the same problem - baffled me for months. It turned out to be a defective radiator. These are aluminum radiators and have extremely small passages that are easily clogged if you inadvertently use or top off with the wrong (i.e. non-Toyota) coolant. Some of these passages had become clogged in my radiator and it had to be replaced. A new radiator solved the problem and is has never recurred. I have exactly this same heater hot/cold issue with my '97 LS400. Thanks for the suggestions -- I'll check things out and let you know what I find. Here is the answer, most likely for all Lexus owners. I have a 1994 SC400. No heat. I found a web posting at http://en.allexperts.com/q/Lexus-Repair-818/f_4590148.htm Follow their directions. This fixed my heater. I think there is a fundamental flaw in the Lexus design. When the fluid level gets low you get a gas pocket that lives in the heater core. This keeps the fluid from flowing through the heater core. I loosened the 17 mm bolt at the top of the thermostat and ran the car at 2500 rpm. At the same time, have the coolant cap off and top off the coolant over and over until the coolant level is finally full. You will get heat after this. Retighten the 17 mm bolt, secure the coolant cap and be happy! If this works, please pass it on. This will save a lot of Lexus owners a lot of grief and money. It took a total of five minutes to fix!! Yeah internet!!!!

Change the themostat. Trust me. Hi Sean Will do. Thanks for the thrust in one direction. Dave

So, it is winter time and my climate control in my 94 Sc400 isn't working to well. Sometimes there is heat, but then there isn't . Even the auto mode isn't working. My first inclination is the thermostat on the engine, but intermitent heating during a single trip in the car suggests that it could be a problem with the sensor for climate control. Has anyone had this problem and solved it? If so, what do I need to do? Thanks Dave