I am new to this forum and hope to get some more info in proceding with my situation. I am sorry for the long post.
-I have a 1996 corolla that I have never had any problems with untill now. I was stuck in traffic today and being that it was quite early in the morning I was not as attentive as I should have been. I noticed some steam in front of my car and when i looked at the temperature gauge it was well up past the red. I was not moving at all up to this overheat and am fairly confidant that the overheating occured very rapidly as I often check my gauges. Anyway, I pulled right over to the shoulder and turned of the engine. The coolant was boiling and had spilled out of the overflow box. Now, I have never had my car come close to overheating before, not even in hours of traffic. This came with no warning and happend quickly. I am aware that the coolant in my car was well over due for a change, but I had no problem at all or any sign of trouble untill today. I stood on the shoulder untill someone driving by had some antifreeze they let me have (thank god for decent people who are willing to help). Unfortunately they didn't have that much antifreeze. I started my car and the temperature gauge rose to its normal position as I got back into traffic. However, after standing in traffic for a few minutes it started steadily creeping back up. I got onto the shoulder and drove the remaining short distance to the service area up ahead. As soon as I started going over 25mph the temperature dropped back to normal in seconds. At the service station I bought some more coolant and refilled my system. After that I drove about 50 miles on the highway and city (I had an appointment that I could not miss under any circumstances). The temperature remained at its normal level throughout the trip and the car performed as it normally did prior to the incident. However, I was not stuck idling in traffic the rest of the way. At the end of the day I got lost driving around the cramped streets of philly and the temperature remained completely normal even with some traffic. I made it back driving about 70 miles with no problem. I now need to know what could have caused this overheat. I am hopeful that there was no major damage done to my engine. I smelled the exhaust when I got home and there is no sweet smell. The oil also looked normal after the trip. I am going to drain the coolant tomorrow and refill the system. I still need to know what caused the overheat so I can fix the problem. The thing is I don't have a mechanic I can completely trust as I have never had to deal with car trouble before. I don't want to go to the toyota dealership as I cannot afford their prices to even look at the car. Does anyone know how i can check to see if the fan is functioning properly? could it be the thermostat? (I can afford the 20 bucks to replace that myself). I don't want to spend more than i have to on this since this is an old car and I don't have the money to have someone do unnecessary work. Any advice would be great. Please don't berate me for driving 130 miles after an overheat. I know it was a terrible idea, but I had no choice and the car performed perfectly.
The cooling fan(s) bolted to the radiator may not be working. These fan(s) come on at a set temperature to force air through the radiator and cool the coolant. A thermostatic on/off switch installed in the radiator controls a relay that controls the fan(s). The switch or relay often goes bad. The system also has its own fuse, I think called CDS Fan. Check this fuse plus the wiring to the switch, fans, etc.
Test the system by starting car and warming it up. As the temperature gauge rises to the red (beyond normal), the fan(s) should kick in. If not, there is a problem, usually the switch. Don’t overheat the car; the fan(s) should come on at 199F.
If the fan(s) are working OK, the thermostat may be stuck or failing to fully open (another common problem). The radiator may also be obstructed, airflow blocked, etc. Check the fan(s) and thermostat first.
If this car has A/C, one fan normally comes on with the A/C. See if this happens when you have the engine and A/C on. If so, this is an indirect way of getting some cooling.
The cooling fan wont do shit when there's no fluid flowing thru the system, what the fan basically does is to "remove" excess hot air from the engine bay, not "cool" the motor.
However I do agree with you that the temp sensor should also be checked.
what the fan basically does is to "remove" excess hot air from the engine bay, not "cool" the motor.
Actually it pushes air past the radiator fins to increase cooler air, so that heat will transfer more efficiently to the surrounding air. Therefor it sorta cools the engine, by flowing air past the radiator. Now it wont cool the engine blowing air AT it, plus if your dont have water moving in the system it wont work. Best thing to do if you notice overheating, is slapping the heater on full blast.
Well, I flushed the coolant today and checked the system further. The temperature is fine, but I did find the fans to be a bit problematic. As the car heats up, the fans don't kick in, but if I nudge the fan on the inside of the radiator it sometimes starts up. I can't tell if its the fan, relay, or switch that is faulty. Also, the car didn't overheat at all even when I kept the engine running for a while after changing the coolant. This made me consider what caused my sudden overheat while in traffic yesterday. I am leaning towards it possibly being as simples as the thermostat. I don't think I can really blame the fans considering I am not even sure if there is anything wrong with them (they do come on when the ac is on). Anyway, my problem of not knowing a good mechanic came up when I took the car to a shop recommended by my parents. The mechanic there told me he couldn't help me because they didn't do electrical work. I still want to change out the thermostat since I understand it is an easy and cheap fix that I can do myself. Can anyone guide me through this procedure. I am not sure where exactly the thermostat housing is. The car is a 1996 corolla with the 1.6L engine. Thanks in advance.
If the cooling fan isnt kicking on like its supposed to, it will overheat in stop and go traffic, as the fan is the way the water gets cooled. Thats also probly why it cooled off once you got moving, as air was being forced through the front of the radiator.
The easiest way to check the fan is disconnect the plug to the fan and run 2 wires, one to your battery + and one to a ground to see if it kicks on, if it does then its probly either the fuse or the temp sensor on the radiator, if not, then its the fan. Just try to make sure you know which is the hot wire.
If the cooling fan isnt kicking on like its supposed to, it will overheat in stop and go traffic, as the fan is the way the water gets cooled. Thats also probly why it cooled off once you got moving, as air was being forced through the front of the radiator.
The easiest way to check the fan is disconnect the plug to the fan and run 2 wires, one to your battery + and one to a ground to see if it kicks on, if it does then its probly either the fuse or the temp sensor on the radiator, if not, then its the fan. Just try to make sure you know which is the hot wire.
The fans do go on when the ac is turned on, so it seems like the fans do work. The problem is probably with the relay or radiator switch. Is there any way I can test the relay? and which one because there are 3 fan relays that I see. I assume that the switch can't be tested and if the relays are fine than it would have to be the switch that is at fault.
do the thermostat dude.. its most likely the culprit. Also push on your rad fins to see if they're not brittle and breaking off, if they break off at the push of a finger, then you need a rad.
If this cooling setup is like other Toyota models, the radiator temp switch must be open and relay no 1 off for the fan to start. The switch should have continuity below 199F but not above this temp. The relay for the fan would be Relay No. 1. If you can find the relay you can do an ohm test and battery test.
The A/C fan on/off operation is separate from the cooling fan on/off operation. If you need to drive, use the A/C fans to help cool the engine until you can fix the problem. Relay no 3 controls normal A/C fan operation. Relays no 1 and 2 appear to be for low/high speed fan and A/C high pressure problems requiring the fan to turn on.
If the fan starts when you move the blades, perhaps something is stuck, or a loose wire. Apply 12V power to the fan to see if it works smoothly.
Find the wires going to the radiator temp switch for the fan. Start the engine, pull the plug and see if the fan starts.
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1996 Corolla overheated in traffic...what now?
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