Radiator Light

[detroitguy]

My very generous brother gave me his 1994 ls400.The car is in great shape afew nicks here and therethe seats area a bit worn but all in all avery nice car; way out of my league.

I live in a cold climate.When I start the car sometimes the radiator light comes on.If I shut the car off and start it again the light stays off.The car is not overheating and the heater works fine(hot air blowing from heater) Should I be seriously concerned?The resevoir level is fine.

Btw my brother has a 1999 400 now.

[silvermate]

my advice would be to check the coolant sensor, it could be faulty and triggering the light.

[SKperformance]

may have a slight airpocket

a bad wire

[93ls400]

I have exact same problem on my 93 LS400. It only happens on extremly cold morning for a minute or less when I start the car than that radiator light disappears. I drive normally after that and so far nothing happens. I checked the fluid level and its fine.

[baul79racer]

Hello I have "91 LS 400. Today when I was driving to go home. I went around a sharp upgrade hill incline about 25 m.p.h. into the corner. It's very sharp.

Anyhow to this situation after climbing the hill with the Lex revving sweetly. I check my gauges and notice the engine coolant light was on. I was not far from home. So I drive home with TLC. I was being easy on it. When I pull into my driveway I check for any leaks and check to see if the level was low. It was not low but just over the top level mark. There's two level marks on the coolant box.

I also turn off the Lex in the process. I cool the engine off with the hood up for awhile. To see if that would help any. And it didn't. It came back on with in minutes. I then talk to a friend who knows cars. He said from your situation that with the speed and g's force going around that sharp corner could offset an signal to activate the engine coolant light sensor to come on. True or false?

Could it also be that the coolant sensor light be sticky?I believe it's not because when you turn the Lex on/off the light doesn't come on right away. When you turn it on to the Accessory position the coolant light works like it should. But that's not the problem. The problem is that it comes back on even for awhile of like 10 min. of waiting before starting again. Any solution to my problem? Do I need a new sensor or should I clean the sensor?

Paul

[RFeldes]

Hey Paul,

What does your temp gauge register?

[baul79racer]

Well for my Temp. gauge. It reads normal like it should in the middle.

I check the car this morning and it was at the lower level. So I added some water so it would be between the two level markers. I then, started up the lex and suddenly in minutes the coolant light came back on. I then proceed to check the level and it was neutral. I then wanted to take out for an test drive up to Newcastle golf course. I got some good speed and warm the lex up thoroughly and then check it at the golf course. When hot, or normal temp. It was above the second level which is normal before the light ever came on. I then proceed on with my test drive. Afterwards, I still bug about the situations. I then, call the Lex dealer in bellevue. The guy said, that You might need to replace the sensor. Before he end the call with me he said try checking the cap on the sensor before replacing the sensor itself. Any good idea of checking the cap? Would that I have any cause or effect of this situation. He did remind me that the service center has lots of sensors.

Paul

[baul79racer]

Continued.... on ...

Today, I did take a trip an round trip of 80 miles. It ran great. The light was on the whole time. It was warm weather here in the 60s in WA. Temp. gauge stay the same even when I was going at speeds around corners. I know that shouldn't effect the problem. I was just letting you guys know how I drive. I was carry a full load of passengers. Plus, an wheel chair for one of my passengers. It was great!

Ran great. I new occurrance I had the cruise control on part of the way and I was accelerating with it because I had two other cars that were following behind. Not lexus but an BMW M-6 and just an Kia. I also use the deacclerating two. not to often. At one point of time the cruise control didn't like my commands with +/- with speeds of the cruise. It then, suddenly shut it self off and made the green highlighted cruise control to go away. I try to regain the cruise on my controls but no responding of any. And it didn't appear the green cruise on the instrument panel. I then, told myself that she playing with me. I then, ignore her and didn't mess with the cruise. When I arrive to my destination for lunch. I then, have my fun with my crew. After awhile, I when over to the Lex and started her up and the green light appear. Then, I shut her down. And finished enjoying my pre-Easter celebration. When it was time to go. I was curious of turning it back on. I did and it was back on normal it accelerate and deaccelarate like it should. I was then happy and feeling great about myself and the Lex again. It didn't occur any new problems down the road. THAT'S TWO PROBLEMS THAT SHE (LEX) PLAY AROUND WITH ME. I know it's long but it's good to share.

Paul

[914lps]

The light on mine stayed on. The sender was bad. The float in it would not float anymore. I took the sender out. Let it dry out. Then JB welded some plastic to the float to make it float. Put in back in, all fixed. Took about 10 Min., time and a few cents worth of glue.

[baul79racer]

Hi again, '91 LS400

The problem got resolved. First thing I tried was cleaning the sensor itself.

There were green crud around the sensor and the needle was stick to the plate. So, no broken needle. Great advise and idea to check. That wasn't my problem.

Just a little clean and there. The light hasn't come on since. Save me a run to the parts dept. It helps to read and prepare yourself before throwing parts at the problem.