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Discussion Starter #1
I just noticed that my radiator fan kicks on and runs a few minutes after I turn the car off. Is this normal? I didn’t notice that when I test drove the car, or the first couple times after I bought it. I had the battery disconnected while changing the timing belt and it has done it every time since. Perhaps that’s just coincidence but still wondering if this is normal or not?
 

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Many cars allow the fan to run after the key has been removed, some cars don’t. They should run anywhere from 30secs- to a couple minutes. Keep in mind the minute you turn your car off the radiator gets hotter as there is no air flow and the water pump is no longer circulating the water. This causes the temperture sensors to kick in and turn on the fans. Again I really only notice mine on hot summer days but have ocassionally heard them run on winter days after shut down . In the winter you probably do not notice it as much as the cooler air helps cool things .
 

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What Wilson said. Be aware that a faulty fan controller/timer can leave the fans on for too long and give you a dead battery after a few hours. The fans should never be running beyond 15 minutes after engine shut-down.
 

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Discussion Starter #4
I see a lot of posts about this on the internet with lots of different options, but no definitive answer, like from a dealership. I have never owned a car that did this and since no heat is being generated after turning the engine off, the fans don’t need to run at this Point. I don’t care about residual remaining heat in the system. The water is no longer circulating in the radiator so it is pointless to run the fans. Not to mention the drain on the battery. I see this as a definite problem. There must be a malfunctioning sensor or something.
 

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Discussion Starter #5
Well I feel pretty stupid. My coolant level was about a gallon low since replacing my water pump. I topped it off and will see if that takes care of it.
 

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Tfret, We are not here to give you bogus answers as it would be pointless to have this forum! Am I sorry you do not like the answer you were given? You did not notice it because you probably were not paying attention to it or it did not need to turn on as it will only do so when it is required! Whether or not you care that there is residual heat in the system makes no difference as that is what the sensors are put in for. Just so you are aware that after you shut off your engine the heat does build up in your engine before it starts to cool. The sensors pick this up and start the fans to eliminate heat to help cool things from the possibility of overflow. The amount of power used in this process on a properly maintained electrical system is minimal unless it keeps running over the 10 minutes in which case you should have the sensors replaced and vehicle looked at as stated previously. There could be other issues however as it appears from your post that you have been working on said vehicle so perhaps the fan plugs were not properly plugged in and after the work they were? Stranger things have happened after working on cars.(perhaps previous owner accidentally disconnected) The second issue is was the thermostat put back correctly or at all? I only have to ask as many of the timing belt kits do not include these and people have been known to put them in backwards or leave them out entirely, which would bring the temperature up on the vehicle and definitely cause the fans to run for long periods. This again would not be the fault of the sensors to cool things but the fault of an improper install. What does your temperature gauge read after a 15 min drive? Furthermore, you have not stated just how long your fan has been running for? is it less than a minute? Less than two minutes? More than 5 minutes? Also what State do you live in and how long a drive and how hot was it outside when you finally noticed the fans running? Only ask as again depending on temps the fans will run longer.
 

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That can cause higher temps and cause fans sensors to come on sooner than normal to try and cool things and stay on longer after shut down.
 

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FWIW, my 06 fan runs for a few mins at times after shutdown. Not all, but I have other cars/brands that do the same. For the reasons stated for taking some heat out, it’s normal. The fan would take heat out of the coolant in the radiator and that should dissipate some heat from the block by acting as a heat sink even if the pump isn’t actively circulating the coolant.

IMHO, it’s good to read responses with a grain of salt as the experience and skill across posters is varied. After all, it’s free advice and a discussion group. Not so much on this forum, but have seen other forums with inexperienced, unhelpful advice. With that being said, I probably wouldn’t call anyone out unless their post was flat out unsafe. Just my opinion.

Back to the point about changing the pump and coolant being low, good find. Whenever coolant is removed to replace a pump, thermostat, hose, etc think it’s a good idea after first refill and with engine cold to then run the engine for a few mins with heater on, rad cap off to top off. Check later or next day when the engine is cold and if needed, add more coolant. Be sure to fill the reservoir.
 

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FWIW: The history of After-run fan cooling.

In the early 1980's with emission controls making under hood temperatures higher, especially on smaller cars with little extra air space, the problem of gasoline percolation (boiling in the carburator) became a problem on hot restarts. Honda started installing the fan timer systems to combat this. Later, when fuel injection became universal, the system was dropped, since the higher pressures in the fuel system almost completely eliminated percolation. By the late 1990's a new problem showed up. The gasoline in the fuel injectors would break down into gummy deposits from heat soak after the engine was turned off. This caused injector sticking problems. Solution: Go back to the after-run system.

Now you know.
 
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