I just got done searching and found a little information but not enough to where i feel comfortbale about the problem.

A couple days ago i was driving and i look down at my temp gauge and it says that my evo is overheating, and overheating bad.. I'm talking almost at the H... When i am driving on the highway it doesnt really do it, but in stop and go traffic, sometimes it will be fine, sometimes it will by sky high. Now i have heard of the recall on the fan controllers on the 03's (Which is what i have), and i havent done that and was wondering if there is any way i can check to see if thats the problem? Also, i have done a compression test which came out perfect, i did a complete coolant flush, and checked to make sure i wasnt leaking anything. it's just weird because i have never seen a temp guage climb and fall that fast and that random before. I'm not sure if it's the head gasket, and my fan comes on and off like it should, so any info will help!

 

just a quick reply, not sure if it relates, my lancer did the same thing: highway good, traffic and it went all the way up to the h. before it was too late i looked under the hood and saw something not connected. some douche who did work on my engine didnt reconnect the fan switch so i was stewing in engine heat. the fan controller is the most likely thing. take it to mits for the free upgrade.

 

sounds like your fan isnt coming on. It could be your HG but my bet is your fan isnt coming on. Get the damn fan controller fixed. Dont you think that'd probably be a good first step? Sounds to me like you added yet another worthless thread to this website and answered your own question in the process.

 

its not random if you go on the highway and the temp goes down, think about it: all the cool air is rushing through at cruising speed and in traffic all the hot air stays in there.

 

Simple test.... drive the car for awhile, like on the way home from work. Park the car in the driveway with the a/c running until it starts to show signs of overheating. Check to see if your radiator fan is on, it should be. The recall work doesn't take long at all. Maybe 15 minutes max, but it's the wait that'll be the killer.

 

why do people insist on flaming all the time??? the kid is asking a question and all he wants is an answer, how is this worthless??? dont read his thread and reply if you dont care, how hard is that??

 

Ok, there are mmaany things it coudl have been. Leak, head gasket, bad fluid, fan not working, line disconnected, etc.. WHO KNOWS. If you dont want to read it, dont do it. If you dont have anything to say that will help anyone DONT SAY IT. You know, it's a simple question. I dont understand why dicks like you dont just keep your mouth shut when you dont have something intelligent to say or somethig mature. Get a life and stop flaming people to make yourself feel good.

 

Oh, Lancerj, i wasnt talking about going up and down random on the highway and in stop and go, stop and go it goes up and down very quickly and randomly. Within two seconds it could be perfect to above the H. I know it makes sense that it goes down because of the air coming in when i'm on the highway, but i was talking about in stop and go. That's what confused me. And stop and go traffic isnt anything about 35mph around here. I will do the test that dubble said to do and let you guys know if i have any problems.

 

. the fan might be on long enough.. the fan could be going bad.. the thermostat is screwing up.. god the list could go on for hours.. dont reply to the idiots.. they will go away.

 

Just a thought....maybe you have vapor around your temperature sensor. When the liquid coolant touches your sensor, temps are normal, but when vapor touches it, temps jump fast. Just my 2 cents...