2002 s430 when idling or at a long traffic ligh the heatgage will go above the 80 then go down when i drive?

Question

while i am driving the needle is at the middle when i come to a traffic stop or idle the car the needle start to rise and go over the 80 .. i  did notice that when it was about the 80 like that the readiator fan was not engeageing or working. i took it to the shop . the guy tested the fan and told me the fan was working however i have no code in the computer so he will need to dive in and need more time so i have to come back ...can anyone tell me what possible could be the cause , i would like to have a frame of refrence as to what is the area i shoud look into ..  thanks

Anonymous · Accepted Answer

Id replace your thermostat because its the cheapest thing to do and then if that doesnt solve the issue Id look further into it and maybe replace the fan. Im not familar with your car but I know my car has what they call a thermo fan switch id try that also before the fan unless you find out it actually is the fan.

Anonymous · Answer

Idling engines will warm up but so long as it doesn't go into the red it's no problem, once you move off the increased air flow cools the engine.

Sounds like the fan or thermostat needs looking at.

You can replicate the condition by leaving the car on fast idle outside the shop

2002 s430 when idling or at a long traffic ligh the heatgage will go above the 80 then go down when i drive?

2 Answers