Ok, before I get flamed for posting the "kinda" redundant information, I had searched the forum and i didn't wanna resurrect any dead thread and it doesn't really fit anywhere.

As you all know our car's fan turn on and could run for 10+ minutes after shutting down if temperature is too hot. Normally we let the fans run to cool down engine or some might have turn key to "ON" then "OFF" and this would turn the fans off which is a big no no.

What I have discovered during the past few days is:

After driving normally (light load 4k to 5k rpm) in a 95 degress weather, parked car, fans doesn't turn on (not considered hot enough to have fans run after shutdown by PCM). If I intentionally turn key to "ON" again and waited for about 10 to 15 seconds or so, the cooling fans will run for 5 to 10 minutes as long as key remains in "ON" position.

Its just an FYI, like I said it could just be redundant info but I think everyone should get some kind of mods to force the fans to run after every shutdown.

 

I was thinking of a secondary electric water pump, for extra flow on extremely hot days, or after the engine shuts down. No idea how I would plumb that yet.

 

1. Perhaps I might have worded it wrongly. I mean if the car decides to turn on the fans after being shut down, its not advisable to stop the fan by turning key to "ON" and then "OFF" which will stop the fans.

2. I'm thinking if I turn the keys back to "ON" after shutting down (which the car decides there is no need to have the fans running after shutdown), 15 seconds later the fan starts running at full speed could mean the car actually needs the fan to cool down due to heat soak or something.

Maybe I'm just paranoid but I surely didn't expect what I said in (2) to happen especially light driving in 95 degrees ambient temperature.

 

iirc, the fans turn on after HARD driving, regardless of outside temps.

 

^^ Was driving with light load (4k to 5k rpm) shift and cruise at 6th at around 70 miles per hour. Turn off car, fans don't come on which seems extremely normal but I decide to put keys back in to "ON" position, after 10 to 15 seconds, fans start spinning at full speed, they lasted as long as 10 minutes if key remains in "ON" position.

 

kk, i was under the impression that its bad to turn them off if the car wants them to run after shutdown. Guess i'm being paranoid, my bad.

 

Exactly! i'm really puzzled as to why the fans turns on after that 15 seconds "ON"... oh well...

 

There has to be some benefit to keeping the fans on. If there wasn't, the manufacturers would not spend the couple of dollars it costs them for a relay and timer.

I kind of enjoy walking away from my car and hearing the fans running. YMMV.

Ken

 

^ lol i like that sound too : )

 

Dont the fan's turn on due to coolant temp rather than ambient temp? An observation, seems like when my car is a little warmer than the standard 180degrees it seems to run at, the fans will kick on when Im stopped.

ie, if my ECT is 200 degrees at shutdown, the fans kick on. If Im at 180 degrees, no fans.

Is this correct or are they triggered by something else?

 

Wasn't saying the ambient temperature is causing the fans turn on but at those ambient under light load non-high rpm driving the fans shouldn't have come on. But it did after shutdown if key is plugged into it.

I'm gonna test it again when I get my AP. I'm paranoid since I only have 1 oil cooler.

 

The fans operate depending on ECT (engine coolant temp), IAT (intake air temp), and the A/C switch.

 

Talk about paranoid, whether the fans are running or not after shut down(in the event I'm at home), I always pop and open the hood. Course I have hood dampers so it's just a little easier, but talk about something that is really kinda useless to do!

I went for coffee this morning, checked the waves, and then came home. Car is in the garage and the hood is open!

 

Hate to wake up the dead "thread" but...
My car has had the fans running after I shut the car down more this year than last. Even if it's only like 70 outside and I wasn't driving hard. It's almost anytime the car reaches full operating temp. I recently had the radiator light come on so I put in a few ounces to bring it back to top. That happened once last summer too. I'm thinking the fan coming on by itself after I walk away from the car an the radiator being a tad low in the reserve bowl may be related.
Anyone??

 

your probably loosing coolant. happened to me. you might need a new radiator if there is a leak or a crack.

 

Well no leaks from what I can see and it was barely low in the reservoir bowl. An when I filled it up I still had the fan coming on after I turned it off. Sooo...