I just got my Koyo radiator installed a couple days ago and I just noticed that now after long drives, the fans run for a while after shutting off the car. I read that the fans are supposed to come on for 10 min after the car is shut off if the engine temp reaches 226F but I never really noticed the fans ever turning on before the new radiator. While driving, the crappy stock water temp gauge actually seems like it's even a little lower than when I had my stock radiator so I think the new radiator is working properly and I would think that my engine temp would be even less likely to reach 226F. Also, it seems like my car hesitates more often at 3k rpm now than before. Any ideas? Should I just take it all apart and check the wiring to the fans?

 

Don't know. My fan usually stays on if I turn the key to the accessory position again after I turn the engine off after a good run. Then, it won't turn off after I pull the key out again! Usually I have to start the car again and turn it off without turning the key again to get the fan to stop. I guess that's just from high engine temps. that need to be cooled down, but I don't know if your new radiator has anything to do with it.

 

You'll probably measure heat soak from your engine even if you had the largest radiator on the face of the planet. When you turn off your car, you're now looking at no circulation of coolant around a very hot engine. Hence heat soak. Since none of the cooler coolant from the radiator is being pumped into the engine, the heat may get REALLY high. I've done the fan mod to my car, and on hot days even when I keep the fans on all the time (which keeps the coolant very near 200 degrees F), the heat in the engine does rise to above 240 after I shut the car off. I usually kick my turbo timer on without turning the car over which allows the fans to kick in. When I restart the car, the temp very quickly drops to sub 210 due to the circulation of cooler radiator coolant.

This may be one of the main reasons to go with an electric water pump in an RX. You can probably aid in the engines longevity if you were able to continue pumping coolant through the engine after you shut the engine off.

 

Did you by any chance do the fan mod also??? With the fan mod, the fans will run for 10 min after you shut down the engine. If not then it is not normal for the fans to come on unless really driven hard. You may want to check the coolant level. Watch your temp gauge carefully.

-Mark

 

Does someone actually make an electric water pump for the FD? I've never heard of that on any car before.

 

hey now thats an interesting idea, the electric water pump. is it possible? this is of interest because no matter what you do you're getting heat soak after shut down, no matter what fans you have running.
i have left my car in the garage with the cooling fans on, the hood up, a floor fan blowing thru the radiator and ANOTHER floor fan blowing cold AC air from the house towards the first floor fan. still water temps go up at least 15C. they'll usually get over 110 at least. its still safe but if its preventable, why not?
more info/opinions!

 

From my research there is at least one manufacturer who offers an electric water pump for the RX. It could be hooked up to both the ignition and temp sensor to turn off only after the coolant in the car has reached a certain temp. It'd also get rid of some of the "belt strain" that the car has as well as possibly aleviating some of the coolant cavitation which occurs with the stock pump at higher rpms. I'd try it, but I'm still paying for of the other goodies that I've done to my car. Maybe after I buy my Fluidyne, I'll look into it

 

Who manufacture's it? That's something I'd definitely look into and post on up once I get it done. That'd be worth the work in my opinion as well as many others I'm assuming. It'd help reduce engine temperatures after shutoff and reduce the parasitic loss like you said. If you got a website and everything, that'd really help me be lazy, I mean help make it go faster

 

It's in the Summit import catalog. Meziere sells two different electric water pumps made out of billet aluminum for "All Mazda rotary". The Summit part numbers are MEZ-WP-116S for the standard duty and MEZ-WP116SHD for the heavy duty. You can also check out Meziere's website at http://www.meziere.com

I'm guessing that nobodies tried this one yet...

 

If noone else tries it in about a month, then I'm going to do it about then. I have a few other things that I need to get done first, but once I look at the stock water pump and altenator, I'll decide what can be done about them and make a plan. If someone else starts it before I do, post the steps. That site has every part you need to do ti though.

 

i'm gonna look into this and maybe do it in the spring.
anyone see potential complications? i couldn't find anything on the site about rotary water pumps. can you post a direct link to that page?
i'd like to mention that dead stock my first 3rd gen would darn near overheat after shut down before i did the fan mod. i think this is the best solution to heat soak i've ever heard.

 

When you open the www.meziere.com page, click on racing products, then electric pumps and that'll bring down a list that has "rotary" in it. Click on that and it gives you all the parts you'll need to put an electric pump on a rotary motor.
Meziere Rotary Electric Water Pump
There's the direct link to the page.