willgq

The fan on my 04 rx8 is running on low while the engine is running not all when the car is turned off. Im afraid the car is going to over heat, engine is very hot when i pop the hood, can someone help?

RIWWP

iTrader: (2)

The ECU can turn on the fans even when the engine is off. This is done deliberately to help prevent heat spikes. If you wish to prevent the fans from remaining on, cycle the key to On, then back off. This isn't recommended however, as you should just let the fans run.

This is entirely normal on RX-8s.

kevinande

You know it would have been nice if Mazda would have equipped the car with an electric water pump as well. Of course we would then have a $900 water pump lol, but it could helped even more to cool down the car in hot weather when it's not running. Of course battery life may become an issue as well? Just thinking out loud.

RIWWP

iTrader: (2)

Yes. The water pump is also responsible for a fair bit of drivetrain power loss that increases as the RPMs do. For that reason more than the cooling, electric water pumps have been a bit of a dream that only a few have pursued. I don't believe there has been any significant success yet, primarily because you still need the power to turn the pump, even if you are just getting that from a beefy alternator.

About the only way that it will work is if you use "free" energy, such as the energy in the exhaust that is otherwise wasted. An exhaust turbine to spin the water pump, as a very condensed and over-simplified example of what I mean.

ken-x8

Ummm... I think the question may have been misinterpreted. Will - are you saying the fan does not keep running when the engine is shut down and hot? Check the fan relay and fuse(s). The fan won't always keep running after shut down, but above some temperature it should run for up to 10 minutes.

When you say "running on low" have you had the car for a while and noticed that it's running slower than it used to? Might be a failing fan motor or bad connection.

If any of this happened to me I'd drag out the wiring diagram, a multimeter and all the patience I could muster.

Ken

monchie

This usually happens when the temperature is very hot and humid, specially living in the desert.

CRO8TIA

Monchie, are you saying your fans don't run after shut down on a hot day, or agreeing with Ken ?

monchie

No...i mean yes, the fan still runs after i shut down the engine when its very hot and humid...sorry for the confusion.