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I have a 93 mx3 SOHC 4cyl. I have been driving the car for about 7 months now. I've always noticed that the car ran hot by the temp gauge (rests at about 2/3) but i thought that the car might just run that hot seeing how its such a small engine. On day after getting home i opened the hood to check on it while its was running and i noticed the rad fan wasn't running and the car was definitely up to temp. It didn't look like it had been running for a while, so i gave it a push and a few seconds later it started up. I think i might need a new thermostat but i just wanted other opinions. Thanks.

Luckily the rad and a decent thermostat are good enough to stop overheating most times. All the thermostat does is control when coolant circulates through your motor once it reaches a certain temp, if it didnt work, you'd be topping out your temp gauge in about 10 mins or so. It sounds like your thermo fan switch, it goes into the thermostat housing and when it gets hot enough, the contact will move and start your fan. It's pretty common for them to break since they are a fragile plastic for half and the other half is metal so they usually break in the meeting point. If you look closely at it, it will probably be cracked and you might have nudged the wire the right way for it to make contact and work. If you see a crack, use a small amount of force to see if it moves around a bit to see if the fans kick in, if they do, fan switch, if not, fan switch and connections to fan motor. Either pocket one or a few from a protege, 323, escort or mx3 4 cyl in a junkyard or buy 1 new for $30-$40. All you need is a 17mm wrench and unhook 1 wire.

Redline322 wrote:Luckily the rad and a decent thermostat are good enough to stop overheating most times. All the thermostat does is control when coolant circulates through your motor once it reaches a certain temp, if it didnt work, you'd be topping out your temp gauge in about 10 mins or so. It sounds like your thermo fan switch, it goes into the thermostat housing and when it gets hot enough, the contact will move and start your fan. It's pretty common for them to break since they are a fragile plastic for half and the other half is metal so they usually break in the meeting point. If you look closely at it, it will probably be cracked and you might have nudged the wire the right way for it to make contact and work. If you see a crack, use a small amount of force to see if it moves around a bit to see if the fans kick in, if they do, fan switch, if not, fan switch and connections to fan motor. Either pocket one or a few from a protege, 323, escort or mx3 4 cyl in a junkyard or buy 1 new for $30-$40. All you need is a 17mm wrench and unhook 1 wire.

Hey thanks alot.

Just FYI, my first RS had a fried fan motor. I chased it for a few weeks thinking...what are the chances that the fan is blown...but sure enough it was. It does happen.

l just had the same problem on my 95 mx3.I thought it might be the fan motor,so went to the junk yard grabed a good fan motor threw it on had it idle and waited to see if goes on,never went on the gauge went almost all the way up so i started to unplug the harness and the fan came on! The plug that connects the fan was shot, just replaced it with new connectors from Canadian Tire and worked great.Hope this helps you?

most times i find that the fan plug is the problem. it makes a bad connection

In my case it was the motor, but I can see where it would be far more likely that the connection would be poor.

Redline322 wrote:Luckily the rad and a decent thermostat are good enough to stop overheating most times. All the thermostat does is control when coolant circulates through your motor once it reaches a certain temp, if it didnt work, you'd be topping out your temp gauge in about 10 mins or so. It sounds like your thermo fan switch, it goes into the thermostat housing and when it gets hot enough, the contact will move and start your fan. It's pretty common for them to break since they are a fragile plastic for half and the other half is metal so they usually break in the meeting point. If you look closely at it, it will probably be cracked and you might have nudged the wire the right way for it to make contact and work. If you see a crack, use a small amount of force to see if it moves around a bit to see if the fans kick in, if they do, fan switch, if not, fan switch and connections to fan motor. Either pocket one or a few from a protege, 323, escort or mx3 4 cyl in a junkyard or buy 1 new for $30-$40. All you need is a 17mm wrench and unhook 1 wire.

Srry i reported this post by accident. Hey man u were right it was that switch i picked up a good one from a scrapyard for 10 bucks and now my fan works good. Thanks.