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overheating ea-81

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ok im going to say this i think its my fan i cant hear it run anymore it used to sound like it was grinding rocks so i think its not but my dad asked if it could be a coolant sensor and i don't know if there is. so my question is is there a coolant temp sensor if so how do i check to see if its working right

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First check that the small black radiator ground wire is attached from the top of the radiator to the core support, it's right on top and only about 2 inches long (phillips screw on each end). There should be a fan sensor with a single wire connection in the lower passenger side of the radiator if it's an EA81 car. Turn on the key, remove this wire from the sensor and connect it (the wire not the sensor) to ground. This should turn on the fan - make sure your fingers aren't anywhere close to the blades when you do this. It sounds like your fan motor may be bad if it was that noisy. You can check the fan motor by unplugging it and connecting the positive and negative wires straight to the battery.

Edited by Crazyeights

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+1 on Crazeyeights post..

 

Last week my sensor failed far from home on my EA-81 and did exactly as he described.

Didn't notice it wasn't running till I was climbing mountain passes on hot summer day....

 

I took wire connector off sensor (single wire) and using spare wire from tool box (always carry a little) , I stuck one end of jumper wire into the connector that went to sensor (wrapped with electrical tape to assure connection-always carry a roll) and the other end of jumper wire I ran to ground screw on top of radiator and secured there. The fan spun when key turned to "on" so ran it like that till I got home hours later to prevent overheating and drove a couple days more till I got the part, worked great... just means my sensor was bad, (single wire/sensor closes to ground when reaches temperature and that creates a circuit that turns on fan=simple circuit, since switch failed to close my fan wouldn't come on.)

 

The sensor is an easy replace once cooled down. Don't confuse this temp. sensor with the gauge sensor. The sensor that screws into radiator is the "fan temp. switch" (named something like that) and has nothing to do with dash temp. gauge. The parts house wanted $38. for the cooling fan switch that screws into radiator... far from home but I didn't play their game when a jumper wires works just fine.

Rock Auto has them for $4. on close out.

 

Yours,(rattling noise) Assure there isn't anything fan blades are hitting like the flimsy alum. shroud got pushed in when tinkering or a nut came loose on motor support and fan is twisting and blade is hitting, etc... Gravel sounds, as you described sounds like bearings bad. To test fan, (I believe it is two wire's, yellow ground, blue poss.) Disconnect the connector (push in on little plastic tab and wiggle connector apart) and use two jumper wires from the fan to battery and test your fan. For replacement check junk yards.. shouldn't be that much and easy to do.

 

I looked at rockauto.com for a fan and noted only fan kits.. not sure why they didn't have a direct replacement..... but a new fan was like $60. Note the new fan's how the blades have a large curve to them, this eliminates allot of the fan noise as I have been told. All mine have stock electric fans as I found replacements cheap at junk yards and just easier to put like for like back in.

 

Good for you for asking questions and learning to fix your car, shows good character and teaches you problem solving techniques. Experiences that last a life time. Sorry so wordy but I just trouble shot what you are dealing with and rattled on a bit... it's great when you can be far from home and fix an issue to get yourself home...

Edited by Indrid cold

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One further note. Before I EJ'ed my old wagon (ECU now controls fan operation) I wired in a relay for the radiator cooling fan. This way the temp sender only has to ground the relay coil to turn on the fan instead of handling the entire current of the fan motor. The fan sensor should last virtually forever in this configuration.

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...I wired in a relay for the radiator cooling fan. This way the temp sender only has to ground the relay coil to turn on the fan instead of handling the entire current of the fan motor.

 

I like that modification...

I held that little bugger in my hand and was curious as to what would have knocked out a simple temp. sensor.

I can only assume that each start of the fan it is hit by a large voltage spike. As you stated, a relay tied in would prevent that...

good info.

Edited by Indrid cold

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Especially as the fan motor and it's bearings or bushings start to wear with age and cause the current draw to increase. The excess load will be handled (or not) by the relay but the sensor will always remain safe in this configuration. Also the actual ground strap to the radiator is one of the first things to get tossed when the radiator is serviced. Not only does it's absence promote electrolysis which you really don't want, it (body ground wire to the radiator) also provides a proper ground for the sensor itself since the radiator is often isolated from the body by rubber bushings.

Edited by Crazyeights

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I had a similar problem last year. The switch wasn't working so I replaced it with a new one and for some reason I still couldn't get the fan to come on so I threw a relay at it after doing some testing. My sensor was grounding as it should but maybe too much resistance? So the switch then just became a trigger. Did a similar mod to my headlights on the other car and surprise sealed beams work fine when given enough voltage.

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ok i tested my fan i just hot wired it to the batt and it worked just fine im a little confused on how to disconnect the sensor and were it is. is it on the back right above what looks to be a plug or some were else also i omed the rad ground wire and it had came out good

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The sender is screwed in to the radiator itself on the bottom of the passenger side facing the engine. It should look like this

 

1S4376.jpg

 

Pull the wire off of it and hook it to ground with the key on.

 

 

ok i tested my fan i just hot wired it to the batt and it worked just fine im a little confused on how to disconnect the sensor and were it is. is it on the back right above what looks to be a plug or some were else also i omed the rad ground wire and it had came out good

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ok good news it works i pulled that connector off and well it was corroded to hell. so i took some sand paper and cleaned up and started the car got it hot and... the fan kicked on!:clap: so i will be replacing the fan soon when i have cash to spend on it but as of right now it works and that's all i need thanks for the prompt help guys:D

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