PDA

View Full Version : Why is my engine fan always running?



geebes
04-13-2007, 07:15 AM
Has anyone else had this happen? As long as I've had my blue car the engine fan has run all the time. :wtf: Let me know.

Colossus20v
04-13-2007, 07:42 AM
Do you have the sensor unplugged from the temperature sensor?

I unplugged mine so that my fan always runs.

Gary
04-13-2007, 02:29 PM
Yes, when the coolant temp sensor is unplugged or fails, fan will turn on all the time.
The sensor is at the bottom of the radiator.

Playfortoday
04-13-2007, 02:49 PM
Cheap part and a 3 minute fix. As Gary said, check the sensor on the bottom passenger-side corner of the radiator, and see if the plug is attached/in good shape. If it is then it is safe to say with 99% accuracy that your water temperature sensor is bad. Just get the new one ready and a bucket to catch coolant, then unscrew the old one and screw in the new one really fast. If you are quick about it, you can do this and lose only a few ounces of coolant. Attach the plug to the new sensor, remove your rad cap, top her off. You will know if you were successful right away by turning on the ignition. If the fan is not running anymore, chances are very good that you fixed the problem. Now, run the engine (PARKED so you can hear if it turns on and so you don't risk overheating if something is still wrong.) until hot to test if the fan circuit is now functioning correctly. Of course, if you get to operating temp and it turns on, give yourself a pat on the back. Just be patient... sometimes it can take 10 minutes of more for the fan to turn on once the engine is warm.

**Special disclaimer: Swap the sensor when the coolant is cool or you will burnz your harbl.

http://img.photobucket.com/albums/v440/Playfortoday/Joke/harbl-54248.jpg

2kSnakEater
04-13-2007, 03:09 PM
I just unplug mine so the fan always run

burnyd
04-13-2007, 03:23 PM
the one coolant temp sensor is unplugged dur dur!

vip09
04-13-2007, 03:24 PM
It will also stay on if you remove your a/c.

VikingJZ
04-13-2007, 04:14 PM
Does it throw a code when you unplug it?

I don't think it does on these cars.

I tried that on my friend's Prelude and it threw an engine light

geebes
04-13-2007, 05:47 PM
No code for me. Wow, thank you everyone. I will check it out, although maybe its a good thing that it always runs if everyone is trying to achieve this?

geebes
04-13-2007, 05:49 PM
Cheap part and a 3 minute fix. As Gary said, check the sensor on the bottom passenger-side corner of the radiator, and see if the plug is attached/in good shape. If it is then it is safe to say with 99% accuracy that your water temperature sensor is bad. Just get the new one ready and a bucket to catch coolant, then unscrew the old one and screw in the new one really fast. If you are quick about it, you can do this and lose only a few ounces of coolant. Attach the plug to the new sensor, remove your rad cap, top her off. You will know if you were successful right away by turning on the ignition. If the fan is not running anymore, chances are very good that you fixed the problem. Now, run the engine (PARKED so you can hear if it turns on and so you don't risk overheating if something is still wrong.) until hot to test if the fan circuit is now functioning correctly. Of course, if you get to operating temp and it turns on, give yourself a pat on the back. Just be patient... sometimes it can take 10 minutes of more for the fan to turn on once the engine is warm.

**Special disclaimer: Swap the sensor when the coolant is cool or you will burnz your harbl.

http://img.photobucket.com/albums/v440/Playfortoday/Joke/harbl-54248.jpg

THanks for the detail, love it! Also, the kitty made me laugh. :D

DarkSideCelica
04-13-2007, 06:25 PM
if it's not the coolant temp sensor, it's the fan relay.... tht's what happened to me

Playfortoday
04-13-2007, 08:40 PM
if it's not the coolant temp sensor, it's the fan relay.... tht's what happened to me

I am glad you were able to be so sure without ever seeing the car. If the relay was bad, the fan would not turn on. It is rare for a relay to stick closed, thus leaving the fan on all the time.

The the OP, not everyone does this. Don't get the wrong impression from the few here that posted that they do this. Most don't. The amperage draw from the fan is large for one, and for two, unless you are running on a really hot day, the stock cooling system does fine.

DarkSideCelica
04-13-2007, 08:57 PM
i changed the coolant temp sensor first, but same thing... fan kept going... i was at a junkyard and i just happened to ask if they had tht relay... tried it, worked, paid $10 and walked out ;)

i read abt the cooling fan issue on the celicas, but i'm glad mine was an easier fix compared to what some of you guys went thru

vndk2r
04-14-2007, 03:32 AM
Gee...thats funny, cause im having the same problem, but my car is a 4AFE. the thing is that ive changed all of the sensors (water temp sensor, fan sensor, coolant temp sensor, relay) and still the fan runs, even when cold. no wires unplugged. still having problem. Sorry, just thought id share.........

Playfortoday
04-14-2007, 03:38 AM
The problem in your case would either be in the wiring or it the A/C system (like an a/c relay) if you have one.

vndk2r
04-14-2007, 03:46 AM
pm'ed