i have 1 1990 ls 400..the low coolant sign came on a few times ...but it was never low...now it just stays on and the temp gague went up a few notches before hot...i change the thermostat...the gauge never goes to hot ...just stay in that same spot ...what may be the promblem

 

my temp runs a few spaces before hot..but it stays there it never moves..plus the needs coolant stays on and i changed the thermostat..what may be the promblem

 

Welcome to CL.
Temp sensor.

https://www.clublexus.com/forums/ls4...ange-pics.html

 

and possibly an air bubble. bleed your cooling system (search for directions)

 

You realize you just jacked an 8yr old thread? Either youre not filling it and bleeding correctly, you have a clog or you have a messed up sensor. I wouldnt risk driving it and blowing head gaskets.

BTW, to add to the thread, my temp sits a little above half with a fresh water pump and thermostat. The old thermostat wasnt closing all the way, so when ambient temp was low it never got to operating temp.

 

Good to see a new member search before asking. It sounds like you're just low on coolant and need to bleed the system. The place to bleed it is the 17mm bolt on top of the thermostat housing, it's the highest spot on the engine. Get the engine to normal temp, turn on the heat, raise the RPMs to 2500. (it will open the heater valve and fill the heater core) Loosen the 17mm bolt, a little, and watch the air bubbles come out. The best time to refill the resevior is first thing in the morning when the engine is cool.

 

I just posted this in the other thread you asked the same question in; It sounds like you're just low on coolant and need to bleed the system. The place to bleed it is the 17mm bolt on top of the thermostat housing, it's the highest spot on the engine. Get the engine to normal temp, turn on the heat, raise the RPMs to 2500. (it will open the heater valve and fill the heater core) Loosen the 17mm bolt, a little, and watch the air bubbles come out. The best time to refill the resevior is first thing in the morning when the engine is cool. Good that you searched, a little, but try not to ask the same in more then one thread. Welcome to CL.

 

thanks i appreciate it .... alot ..so i take it that changing the thermostat doesnt release the air bubbles

 

thanks and what if the two fans in the front not working

 

i have a 1990 lexus ls 400.... i went fishing 2days ago everything was fine..i was paked on a hill...now all of a sudden my temp gague reads close to hot and just stays there...i even change the thermostat but no change..it doesnt run hot but just looking at it there kind of scares me...dont wanna blow a gasket...what may be the promblem

 

The problem is you're asking the same question in 3 different threads, 2 that you started. Noone wants to read the same thing over and over again. The answers were already given to you in the other threads. Read the answers and post in one of the others. This one should be stopped.

 

If you changed the T-stat then you let air in. If you didn't bleed the system afterwards then there's still air in there which you need to get out. If the fans aren't working then see if the sensor on the radiator is unplugged somehow. Check the sensor and check the fan motors, although I don't see why both motors would crap out at the same time so it might be in the wiring.