fan on when engine hot?

[hahaitzskippy]

i need to confirm because my friend does not believe me.

1) drive the car until engine is hot.
2) park the car, idling, fan turns on.
3) turn off the engine (engine is NOT running) but left the key in the "on" position.

my question - engine being hot, ecu being on, should the fan be on and running to cool down the radiator?

it does in all my toyota's, my friend's honda's.

my friend in his nissan does not believe me.

can someone confirm?

[PEZi]

some cars do some cars don't... it has to be an electric fan for one.....

[Jesda]

I normally resolve this kind of problem with violence.

[hahaitzskippy]

some cars do some cars don't... it has to be an electric fan for one.....

07 g35

Yes it's an electric fan. He also claims that infinti's master mechanic at the nearby dealership confirmed that the fan should not be on

I think he's an idiot and blowing smoke

[MinisterofDOOM]

It depends on how the fan is wired. Most of the time, auxiliary electronics like fans can't tell the difference between a car that's "on" and a car that's running. That's why you get a thousand error lights if you just turn the car ton "on" and don't start it. A lot of time A/C is trying to work as well, but obviously can't without the compressor turning.

There's no benefit to the fan running with the engine off, though; there's no coolant flow. You're cooling the radiator but not the engine.

Bottom line:
If the electric fan has power and its thermostat sees that the engine is hotter than a set point, the fan will come on. Fan doesn't care if the car is running or not.

[IanS]

It depends on how the fan is wired. Most of the time, auxiliary electronics like fans can't tell the difference between a car that's "on" and a car that's running. That's why you get a thousand error lights if you just turn the car ton "on" and don't start it. A lot of time A/C is trying to work as well, but obviously can't without the compressor turning.

There's no benefit to the fan running with the engine off, though; there's no coolant flow. You're cooling the radiator but not the engine.

Bottom line:
If the electric fan has power and its thermostat sees that the engine is hotter than a set point, the fan will come on. Fan doesn't care if the car is running or not.

My max will run the fan KOEO, but only if the coolant is hot enough. I have to really flog it to get enough heat in the system. Typically the fan only runs for a handful of seconds at a time, because the cooling system is so efficient.

[hahaitzskippy]

Bottom line my friends an idiot.

[93coupe]

Bottom line my friends and idiot.

Pot ---> kettle.

[scotty-2-forty]

some cars do some cars don't... it has to be an electric fan for one.....

I giggled.

[Jesda]

Bottom line my friends and idiot.

Pot ---> kettle.

You do not smoke pot from a kettle.

[Urabus GodofTraction]

There's no benefit to the fan running with the engine off, though; there's no coolant flow. You're cooling the radiator but not the engine.

Second Law of Thermodynamics comes into play. Fan on, engine off helps. Not as much as if there was coolant flow, but there certainly is a benefit.

[Mr1der]

I normally resolve this kind of problem with violence.

I'm a fan of violence.