Forever22@msn.com

i just had my fan rewired to run all the time on high setting ,what a difference in temp. i was stuck in traffic in 93 degrees for a good 20 min ,the needle never moved above half, i dont care if fan motor burns out quicker cooler temps are worth it. i have a question, i changed the stock air box to a apexi intake ,should i cover the hole that is now there because of the duct that went to airbox. the stock intercooler might suck in some warm air , but at least some fresh air is getting to the new intake

Red Rotary Rocket

Forever,

It's good that you've got your water temps down, but I think something may be wrong with your cooling system. I have spent lots of time in 100+ weather with the AC on, and never had the car hot enough to make the gauge move above half way. The thermostats are a common failure point on these cars...that might be your problem. A new one costs $15, so it certainly couldn't hurt anything to change yours and see if things improve. Overheating is NOT something you want to take lightly. It WILL destroy your motor.

I would cover that hole in the intercooler duct, it should help intercooler efficiency.

Forever22@msn.com

when u put ac on it auto turns fan on ,i think there was a fan switch recall or something to that effect i dont know if my fd had it . the car has never overheated. but in hot days bumper to bumper traffic the temp gauge has moved i changed thermostat and flushed coolant ,i dont understand why piston engine cars fans stay on all the time and rx7s dont,anyway mine does now and it works like a charm , 50k mi and 8.5 compression for a orig motor it must run cool enough

Red Rotary Rocket

Yeah, using the AC turns the fans on, but on my car, running the AC still gives higher temps, despite the fans. I have a Power FC so I can see what my temps are. On a really hot day w/o the AC I might run 95C water temps, and with the AC on I'll run 105C. Using the AC is worse than not using the AC even though the fans are running.

When the dealer does the fan recall, they install a little black box next to the ECU. The purpose of this box is that if your temps are too hot when you shut off the car, the box will keep the fans running for an additional 10 minutes. A nice benefit of this is that the black box has an extra wire which, when grounded, will run the fans for 10 minutes anyway, even if your temps were normal. This does a decent job of reducing heat soak. If you connect the wire to a switch in the cabin, you can switch your fans on at any time when the car is running..also a nice benefit.

Having good compression doesn't necessarily mean that you haven't sustained damage from overheating. Typically, an engine damaged by overheating will run perfectly fine for a while, then after a few months, it will start to spew white smoke when you start it and the cooling system is always needing to be refilled. The compression might still be fine though. Don't worry...I'm not trying to say "Dude, your motor is toast" I'm just pointing out that damage due to overheating can sometimes take a while before you see the effects.

Since you've already changed your thermostat and flushed your coolant, how about sealing up the gaps around the radiator. There is a foam strip that runs along the bottom of the radiator on the underbelly tray. Over time that strip wears out and stops making a seal, leaving a nice gap where air can flow around rather than through your radiator. Just look around and see if there are any gaps that you can close up with a little foam. Some guys have seen a really big improvement in cooling after sealing up the gaps around the radiator. Give it a try.

Good luck!

rynberg

You do NOT want your fans to run on high all the time.

*car will take too long to warm up

*in highway or cruising conditions, car will run too cold and the ecu will run in warm-up mode

*warm-up mode=too much fuel and reduces boost to turbos

Do the Dave Disney fan mod in which you can turn the fans on anytime you want. Personally, I just drive around with the parking lights on which turns the fans on at a much lower temp.

Sealing the edges of the radiator is a good idea. I've yet to do that on mine.

WhtRocket

Uh, department of really stupid quesitons here. Are you running the AC with the temp to max hot and the fan on 4 position? This works pretty good for me.

trigeek37

"i have a question, i changed the stock air box to a apexi intake ,should i cover the hole that is now there because of the duct that went to airbox. the stock intercooler might suck in some warm air , but at least some fresh air is getting to the new intake"

yes - according to the Great Lakes head Mazda tech, it is important to plug the hole that the big piece of plastic used to send air to the air box. I took a piece of dense plastic & milled it to fit. then I attached it to one of the mounting points that the cover went to with a small piece of alum. works pretty slick, though it doesn't look very stock.

trigeek37

what is the appropriate thermostat to upgrade to? I have asked a couple of times, and have searched quite a bit.... anyone have a part number? that would be much appreciated.

Red Rotary Rocket

WhtRocket, was this question directed to me or the original poster? If you meant it for me, I was not talking about my temps when using the AC to cool down the engine....I was referring to my coolant temps when I use the AC to cool down me Fans on 4 and full cold...that makes my coolant temps the hottest. Since I don't really have a problem with cooling under those conditions, I've never had the need to try it on full hot to see how temps are affected. My point to the original poster was that even under the worst conditions, I don't have a problem with overheating...since he is having problems, I used this as an example to demonstate that something is not quite optimal with his cooling system.

Forever22@msn.com

okay ,i get the dumbass award of the week i removed some of that foam because i thought some of the air might make it to the engine bay. what is the fix, duct tape?

Red Rotary Rocket

I went to Home Depot and just looked around....found some long foam strips for sealing air ducts. I just used a little weatherstrip adheasive to glue it to the belly pan to replace my worn out foam. It's been holding up very well.

WhiteRXseven

Wait a minute....

I recently pulled my ECU out,
and I saw the lil Blk box next to it, with
the ground wire screwed down on teh ECU braket,
Grounding it out...

and Hey.. MY Fan doesn't RUN 10 minutes after i turn the car off.. Only maybe if the Car is HOT, but only when HOT.. Whats up?? something wrong?

Red Rotary Rocket

WhiteRXseven, I don't know if something is wrong or not, but look around and see if you find a single wire that is hanging there with no connection at all. I think the wire is black and has a female spade connector on it. That is the one that runs the fans. If that turns out to be the wire that is permanently grounded on your car, then yes, something is wrong. If that wire is permanently grounded, your fans should be running all the time while you are driving and for 10 additional minutes after you shut the car off. There is a catch though....if the car was not running for at least two minutes, then the 10 minute timer won't run. I will make the wild assumption that you are driving your car for more than two minutes at a time

93TTRX7

Mine works like this...I turn the car off first...then I take the switch out, put it back in and turn it to on (but don't crank it)...let the fans turn on...leave them on for approximately 2 min and turn the key off and pull it out...fans should run an additional 10 minutes after the car is shut down.

skotx

Congratulations, your ECU is working correctly. The fan recall runs the fans for 10 minutes only if the car is hot.

3rdGenLuvr

Whats considered HOT? I have NEVER heard my fans run after turning the car off.....NEVER! (well Ive ownly had it since Oct.) When I put in my PFC I remember some lil box(relay?) attached to the ECU.
Is there a way to test it?
And since the lil black thing was there does it mean it had the recall done?

Mahjik

iTrader: (1)

Check this thread on "supposed" testing of the fan circuit:

https://www.rx7club.com/forum/showth...threadid=84470