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The radiator fan spin on a high speed after turning off the car. This happened today. Turned the key to on and Turn to off, fan turns on again a 2nd time. Inmediatelly, I checked the temperature gauge and it was reading less than half of the range. If it normal?
 

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Wiring diagram indicates radiator fan relay could stick and cause this problem. Suggest swapping fan relays and see if problem is addressed. Relay is in underhood fuse box.

If not, the PCG could be commanding radiator fan to run due to overheating on shutdown. Manual (03-06) I have does not suggest this strategy is used, but it was a feature on Accords for a number of years to prevent head gasket failure from heat soak.

I found a wiring diagram for your model at BBB Industries website.

good luck
 

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I don't know specific to the 2nd gen MDX... However, it's common for vehicles with electric fans to be able to cycle the fans for a few minutes after engine shut-off.

When the engine cools down do the fans shut off? If so, I wouldn't be surprised if it was functioning as-designed.
 
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Curious how running the fan would help with engine block heat soak if the water pump is not being driven by the engine.
the fans still move air across the engine block, which helps pull heat away.
 
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I never had my accord hit the fan after I shut it off, in fact every time I shut it off while the fan was in motion it promptly turned off. Not saying that it doesn’t, but it never did for me.

2010 btw


Sent from my iPhone using Tapatalk
 

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That could be a bad sign. My fan has never turned once the motor was turned off until after I had all motor mounts replaced. They removed so much crap including the radiator fans to get to the mounts. Anyways, on my way home, it began to run hot. I made a u-turn back to the shop. My radiator was leaking. I blamed the shop and they complied and they dropped in a new radiator. Fast forward a couple weeks. My mdx began to run hot yet again, but no leaks. The fans started kicking on once I turned the motor off. I go back to the shop, they say I'm low on anti-freeze. My next question, is where is it going. They topped it off and said bring it back. Well, the next visit was by tow. Head gasket blown!!!!!!


The shop is covering this also. The machine shop says the heads are fine. Just need the gasket kit and they are replacing the rubber valves.
 

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so the fan is running with the ign off and key out? which fan? pass or drivers side? how long? will it shut itself off after awhile?

i too had a 91 accord that was designed to do this, i dont believe the mdx was designed this way tho.
 

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Just to clarify most ACURAS and HONDAS after 2000s will turn on the Main Fan after the car is shut down to cool down the antifreeze in the radiator!!... THIS IS NORMAL! If you live in the South Cali you will now as this is basic routine after long periods of idling in traffic and 120°F outside.

And yes this is to cool down the RADIATOR ANTIFREEZE in order to being cooldown when the engine starts again.. The idea behind this is that if your engine overheats you will most likely shut it off and let it cool down, After re-start the Antifreeze entering the engine will be cooled off.

So if your car is doing this, Its more than likely the weather is HOT or you have an issue with your cooling system.
 

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Just to clarify most ACURAS and HONDAS after 2000s will turn on the Main Fan after the car is shut down to cool down the antifreeze in the radiator!!... THIS IS NORMAL! If you live in the South Cali you will now as this is basic routine after long periods of idling in traffic and 120°F outside.

And yes this is to cool down the RADIATOR ANTIFREEZE in order to being cooldown when the engine starts again.. The idea behind this is that if your engine overheats you will most likely shut it off and let it cool down, After re-start the Antifreeze entering the engine will be cooled off.

So if your car is doing this, Its more than likely the weather is HOT or you have an issue with your cooling system.

Maybe so about the fan, but I have been driving Honda/Acura since 96 and I have never had one that a fan has turned on after the engine has turned off until my radiator blew. Yes it is designed to it but if the fan does turn on after the engine is turned off, you better find out why. My fan was turning on with 40 degree weather.
 

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The why is simple, The anti/freeze is abnormally hot. The fan will shut off after the antifreeze is cooled to spec.
This is why there is no set amount of time given to this task, It can cool down in 2 minutes or 5 regardless the fan will remain on until the antifreeze is at normal operating temp.
 
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