Does "after cool" go away with an aftermarket ECU? "after cool" meaning the fan coming on even after you turn off the engine and remove the key.

Mine used to do that with the stock ECU. Not anymore. Does it make that big a difference to engine health/longevity?

 

Please state you car..
I am assuming FD???

 

My fault... 93 RX-7, yes. I needed to get my post counts up, so these were very rushed questions.

Right now the car is in the shop for a rebuild, along with several other things.

But the way it was before, as it pertains to the topic... stock engine with a PowerFC. It was after installing the PowerFC that I started noticing the lack of "after cool".

 

I have a '95 with the Power FC. It too lacks "after cool". Since it's my weekend warrior, and always ends up back in my garage after every drive, I always pop the hood. Just gives me piece of mind that my engine and all that other stuff in the bay (Rubber hoses, electronics, etc) aren't being baked.

 

Ahhh, I see. It's good to know I'm not the only one then.

 

There's a small wire that run's off the stock ECU that's used for diagnostics. When you ground it (and leave it grounded), the fans will run for 10 minutes after shut down. Apparently the previous owner of your car did that mod. This might explain it better ---> Cooling Fan Modification
It does next to nothing for cooling the engine, but did serve to pump ambient air through the engine bay and maybe relieve some of the heat-soak baking of underhood components that takes place.
When they installed the PFC ECU, obviously that modification was removed and the fans no longer run for 10 minutes. The PFC doesn't have that wire or have a similar function. Not a big deal. In the summer whenever practical I simply open the hood on my car. Much more effective than the fan mod anyway IMO.

 

Wow (this is one of those moments where someone says something and completely reverses your thinking)... so I've had it backwards this whole time thinking this was a factory function, and now it's actually back to factory.
Very good info! Thank you sir.