daddyduke

Hi I have a 03 gs430 with 157k miles.I noticed my car temperature gauge trying to go up on me.But it only occurs when Im diving stop light to stop light.I can put it on the freeway and it runs at normal temp.so far I changed the radiator cap temp sensor.replaced coolant 2x new radiator. if it's the water pump wouldn't it overheat all the time. Any insight would be helpful thanks.

Mr Jokster

iTrader: (8)

I dont see thermostat change, did you do that? If it were the water pump, no, not necessarily would it overheat all the time, it may be spinning just enough to cycle some water. If thats the case too, it can be the pulley. But check the thermostat, focus on the gasket around the 'stat.

daddyduke

Okay ill do that tomorrow.Anothrr thing do I have to use gasket sealer.please dont flame me I just want to do it the book.

boosteddsm

Likely the fan isn't turning on. Bad temp sensor, relay, or fan.

GSTim

iTrader: (1)

Sounds like a cooling fan issue.

daddyduke

I checked to see if the fan was coming on and and both were working

daddyduke

can I ask you a dum question when do my fans are suppose to turn on I think I may have hooked them up backwards when I changed my radiator.

boosteddsm

Did this start right after you changed your rad? Start your car while it's cold and turn off the ac. At least one fan should turn on before it starts getting too hot. Is your CEL on?

daddyduke

yes my fans only turn on when the car is fully warmed up.I disconnected the ac pressure switch to have the fans always running into I figure it out but are you saying one fan should always be engaged while the car is on?Also I had a check light about six months ago for tge the upper temp sensor I got the cheapest one from rock auto for like 4 bucks.

daddyduke

sorry for the late update it was the stat got a new one along with the gasket from Lexus been running good for some months now fan kicks in at idle as it should.

GS43001

Help...
My GS 430 is Overheating and Heater doesn't blow hot air.... I can't see from where antifreeze is leaking.
After filling my expansion tank twice, it is empty within 3 miles....Appears no leak in it.... Appears my fans are not working as well.
If fans are out, will the expansion tank empty and overheat?

TrueGS300

Get it to a shop for a leak check asap. You definitely have a leak and are going to blow your engine if you keep driving it without coolant. The fans are activated when the temp sensor reaches a high enough reading, but if there is no coolant around the sensor, or an air pocket it will not give a reading that would tell the ecu to activate the fans. Running the fans with a/c on can be helpful to get to where you are going in a pinch, but that still only works if there is coolant in the system being circulated. The fans blowing through an air filled radiator will help nothing.

lexo98

iTrader: (2)

Sounds like you might have air trapped in the system. Like said before with those air pockets your fans won’t turn on and you’ll overheat. When the engine is cold take the radiator cap off and start the car. Turn the heater on full blast and you should be able to see air bubbles start to come out of the radiator as the coolant circulates. Just keep topping it off with water/coolant. Also keep an eye on the temp gauge