Radiator fan staying on (v3 Sti)

[Firenza]

I noticed today that my radiator fan is coming on once the car reaches temperature and then staying on until I turn off the ignition. ???

The temp remains stable at the half way mark as normal. Theres no CEL coming on and driving the car it seems totally normal, and the heater blows nice and hot.

I found this thread, but its not exactly the same problem as mine.

http://www.clubsub.org.nz/forum/index.php/topic,3528.0.html

If its anything todo with electrics im hopeless, so what do I need to do to check the relays? Im kinda needing a noob walkthrough of what else to check and how :-\

I ran the error reader, and it threw up a code 12, which I believe is something to do with the starter, so prob not related :

Cheers

[Ninja8)]

hi there mate..just guessing at the top of my head. it could be a sensor thats got to do with the cooling system. example..coolant temp sensor etc...

however..im sure others on here will be giving you a hand soon.

good luck

[Guest keltik]

Code 12 just means the starter wasnt running when you checked the codes. No biggie.

I'd plug in the green diagnostic connectors under the steering column and switch the ignition on, make sure the fans cylce on and off properly. That will make sure the relays are ok.

If they cycle properly, its probably a coolant temp sensor problem.

[Firenza]

Sweet. Cheers, I though code 12 was a bit of a ghost code.

I had a look for the green connectors when I checked the other codes and couldnt see them, only found a weird pinkish connector about an inch wide. Could they be hidden somewhere far further up???

[Guest keltik]

Sometimes they are tucked away or taped up. Just follow one of the main thick conduit bunches near the steering column and the green connectors will come out of it.

I think they are on a different trunk to the white/black read memory connectors.

[Optical]

most likely a faulty coolant temp sensor, that's the only thing that controls the fans. You'd have to stick a ohmmeter over the sensor pins, easiest to to this at the ecu end

unless it's somehow a faulty relay, unlikely. The relays are in the engine bay fuse box from memory, so plug a new one in to test

a select monitor could read all the sensors in realtime and tell you if they are behaving

of course your car could be overheating and everything else fine

[Guest boostin]

Are the fans blowing cold air after a while? Prob a stuck thermostat.

[Firenza]

awesome, ill check tomorrow. anything else I should check while im at it?

Funnily enough after I went for a drive after work today, and the when I pulled up at home, the fan was off!! I went out later, and it still stayed off. Hopefully its not swapped the other way and now stays off

Optical, what pins should I test, and do you know what the should read? (I'm a numbskull when it comes to electrics!) I have a mate who can test them, but I dont know what to let him test! Relays I think (THINK....) i can do myself.

Whats a select monitor? Where can I find one? Sounds like a good idea!!

I really REALLY hope its not overheating! The temp dial seems to be behaving, its heats up, and stays at half way. Hopefully the dial is true!

Boostin, the heater blows hot enough to kinda hurt my hand. I havent left it on for long though, only about a minute. Should that be long enough?

[Guest boostin]

Not the blower fan, the radiator fan.

[Firenza]

oh right, i believe so. cold air seemed to be coming from places around the engine bay. I didnt want to test to much as I cant really see much, and I dont want to stick my hand down there in the dark ;D

Other then that, my engine bay seems to be fairly hot. That might be me seeing faults when there are none! :

[Guest boostin]

Cold air from the radiator of a hot engine says the thermostat is closed. You have either a stuffed thermostat, or coolant flow issues.

[Firenza]

okay, how can I test it?

[Guest boostin]

Just get a new genuine thermostat and gasket. Its not worth the mucking around testing it. No-one ever tests them correctly anyway.

[Firenza]

I realise that ;D I remember reading something about putting it in a jug of water at correct temp and seeing if it opens, but thats far to much effort.

I ment is there a way I can decyfer if its either the thermostat or the coolant sytem being blocked.

Also, I read that the thermostat is in the lower radiator hose, is this correct? I guess im gonna have to do the coolant again? Which is bloody annoying as I only did it a little while ago.

Oddly enough I smelt my coolant tank, and for some reason it smells a bit like sherry ???

[nzkaosnz]

check ac isnt on

[Guest boostin]

The flow through the heater core is what opens the thermostat, so any blockage in the core will restrict flow to the thermostat and it won't open. However you say there is plenty of heat from the blower fan, so I'm picking its not blocked.

Try the cheap option first and replace the thermostat.

[Firenza]

If it was the themostat, and its stuck open, so its basically constantly cooling the engine, wouldnt my car find it difficult to reach operating temp? As it doesnt, It gets warm the same in the same distance it always has and sits nicely at halfway on the gauge.

And if it was stuck closed wouldnt it overheat furiously?

Oh, how much should coolant should I have in my expantion tank, as there wasnt a lot when I checked it cold this morning (Never really notice how much there usually is in there )

[Guest boostin]

I don't think its stuck open or stuck closed, just not opening properly.

Keep driving it with the fans on and you'll cook it. Been there, done that....