Hey guys... Dunno if anyone else has had this problem. Tried to search but didnt know what i was looking for. After turning off my car, something that sounds like a fan, or perhaps some belt running continues to sound from the engine. i havent looked under the hood to see whats running, but its happened like 3 times. I just have to go in and put the car on battery, and turn it off, then it stops. I know this is vague, but i dont know how else to explain it. figured id as here first before i went running to the dealer, n have them unable to reproduce the occurance, cause it seems almost spontaneous.

 

Perfectly normal. After hard driving or when it is hot the cooling fan will run for quite a while. Perfectly normal.

 

okay so i should allow the fan to run? or should i continue my method of turning it off? Thanks for the info tho.

 

For the love of your engine man, let the fan run.

 

Yeah, it is fine to let it run. The fan runs when the car is shut off while it is hot. Alternatively, you can let the car idle for a while to cool circulating the coolant in the radiator for a minute before shut down.

 

May want to read the Manual that came with your car.

 

The 'after cooling' that is carried out by the RX-8 is to counter something called heat sink, a phenomenen that occurs on any 4-stroke engine.

The instant you turn the engine off the flow of coolant inside the engine stops, because drive to the engine driven water pump is stopped. Heat still in the engine can no longer be removed by the flow of coolant, which can cause higher temperatures and cause hard starting.

By operating the cooling fan after the engine has been shut off, it is possible to keep the coolant flowing to a certain extent, by using the natural capilliary (?) effect - hot coolant rises to the top of the engine/radiator, pushing the cooled coolant down through the radiator and lower hose into the engine. (That's why the top radiator hose is always as hot as hell and the lower one not so hot.)

For your information, power is supplied to your Metering Oil Pump and Electronic Throttle as well after the ignition is switched off (just for a few seconds, to carry out self-checks).

 

I'd only experienced the fan running for the first time yesterday; seemed like it was running more than 10 minutes! Since I'd put 6K miles on the 8 and not experienced it before, I thought there was a problem. But, thanks to your explanation "Mr. M," I understand what was going on - great explanation! Thanks.

 

I shut the car off and sat in it a while yesterday waiting for some friends to catch up and I heard the evap system test occur. About a minute or two after shutting the engine off I heard a little pump click on and whirr away for about 45 seconds coming from the fuel tank area. I'm guessing it was the test pump pressurizing the fuel tank and checking for leaks in the system.

Not what you heard, which was definately the fan running, but just another thing which goes on 'behind the scenes' with the car after you shut it off.

 

The EVAP system works like this.

http://forum.mazda6tech.com/viewtopic.php?t=16


Your car has a list of functions it performs after you are already walking away..

 

Reviving an old thread, I realize it but it's getting hot here in Houston and the after-cooling fan is running to beat all hell. It ran for fifteen to twenty minutes tonight. A week ago, I parked at the airport and when I returned a few days later, my battery was dead - completely dead. Today at lunch, the starter sounded weak (you know the dying battery sound). I generally have a habit of turning of the a/c when I kill the car so as to lessen the load on the battery when cranking. At lunch today, I had not done so. When I heard the drained sound of the starter (sluggish sound, whatever), I cut the key off and flipped off everything electrical. I cranked the car okay after that. Now I get home and realize that damn fan runs for fifteen to twenty minutes and I'm wondering "can it (does it) drain the battery?

As I write, I realize that in normal function, no device is going to drain a battery like my was drained when I got back to the airport. I mean the electric locks wouldn't even work. Kaput!! So obviously that was either another event or the dang fan is sticking "on". Anyway, I'll go ahead and post the thread to find out if anyone on here has connected a power-drain to some function (proper or otherwise) of the after-cooling fan.

 

My fan ran for 6 min after I shut the motor off here in Houston.

 

My fan ran for about 10 minutes one time, when I first got it. It wasn't hot out, the engine had been driven for about 15 minutes and wasn't driven hard at all.
This fan concerns me, because it is all battery power that's running it. I have heard other cars cooling fans running after they are turned off, but they usually are very small fans with little noise, this fan sounds like the engine is still running. It doesn't seem to have any rhyme or reason as to when it decides to kick on either, sometimes I expect it after hard driving and nothing?

 

hard driving gets everything upto temp and circulating through radiator and oil coolers which are helped by airflow. short drives or drives in stop and go in the heat do not allow for suffiecient cooling. so the fan runs afterwards to bring the temp down. remember that more of the cooling in the rotary is handled by the oil than in a piston so the cooling requirements are different. hence longer fan times.

 

I realize that the fan is suppose to come on at times and I am used to this, but yesterday I pulled in my driveway after normal driving and went inside (fan was on and I new it was). Well I came outside after about 20 minutes and the fan was still running. I am used to my car by now and feel very strongly that this is a problem. I got in the car and tried to start it. It started but was turnning over slower then normal. I did some searchs but couln't find anything other than "this is normal" but it really seems odd. It has happend twice over the 5 months I have had the car. Just my 2 cents

 

Z1n
You have a problem man. Get it to a dealer. This shouldnt be happening. If the fan is running so much that it is draining your battery dead then thats not right. This car runs hot especially if you dont have speed. For example I have measured pre filtered air(engine intake) and at 45-50 mph on an 92 degree georgia day it was 113.8! Same day on the interstate at 70mph(or so) and it was 95.9! (Ram air affect!) This car needs speed to cool! It sounds to me that you have a bad sensor.
PS afterthought :your coolant level is ok right?
olddragger

 

Yea my coolant level was/is good. I am taking it in this week. I'm going to try to get my AC fixed too. That burst of hot air it emits is terrible in Dallas when it’s a hot day even with tinted windows. Thanks for your advice olddragger.

 

I don't believe your battery drained because of the cooling fan; nor from leaving it sitting for a few days. Something else may be wrong. If you have to park it in an airport lot, you may consider a VW solar battery charger they use in a lot of their sale lots on VW cars - I think it puts out .8 amp or something - enough current to offset the trickle drain from modern computers that are always doing something on modern cars. I've seen them on Ebay...

 

Probably do have some other problem, like a bad battery. Sometimes during shipping from Japan something electrical can be left on, like the ignition switch, and the battery will be drained. A dead battery can sulfate and be damaged. Charging it at the port or dealer will not cure a sulflated battery. Go to your dealer and ask for a full battery load test.

Turning the AC off before turning the engine off will reduce the fan running time. AC causes more heat so the main computer has different settings for the temp sensors for the fan.

 

trz750,
Good advice on turning the a/c off before you kill the engine. I didnt know that the computer read it differatly. Heck I always turn ALL electrical stuff off before I shut down. Even the radio. Habit I guess. I also let the car idle for a minute or so. Whatever Z1N problem ends up being it should be covered by warrenty
olddragger

 

Yea that is good advice. I always leave everything on including the ac and never really thought about it, but I will now. If my battery ends up being bad, Im gonna try to get something better even if I have to pay the difference. Now that I think about it, arent batteries pro rated? I would have to pay for a battery even if it was faulty? I guess i'll find out when I get it in the shop.

 

The was posted a few months ago. I had it happen and it FREAKED ME OUT - lol - but I came here, posted the question, got the feedback and now it's no longer an issue. I love you guy.

 

[B]it can also be the alternator thats still on...it needs to charge the battery again dont it??

 

the alternator is spun by the crank pulley. It only charges while the engine is running. I havent seen any rx8's that the fan was running still with the key off. On some of the 6's and mpv's the cfcm (cooling fan control module) have failed and the fan will stay on or operate erratic.