ZeroBanger

I don't know what to do about my overheating. I have changed everything in my car. I have new radiator fans, Koyoradiator, new AST, all new hoses. I was running really hot so I diluted my coolant to something like 85 water 15 coolant. on saturday it was very hot and I hit 114 on the highway. I took it into a shop today, they checked my thermostat and said its fine.

they blamed it on my coolant and said it had too much water. That sounds weird to me, seems more water should make it run cooler. he flushed it and put 50/50. I do NOT like that, and i'm getting frustrated. Its like 9 AM and not even hot out..he test drove it and put the AC on high and according to him the temps "never went over 108". WTF...it seems like 108 is ALOT to me. what happens when its 100 degrees out?

I told them to test it later over lunch when it gets warmer. I am lost now. even my water pump is new.

everyone i talk to with a FD says they rarely go above 95.

GsrSol

Is it losing coolant at all? Maybe your "new" waterpump has went out or was bad, were you having the same problem before the new wp? Have you replaced the radiator cap?

FstFD3SPOWER

Did u removed belly pan? go with 100% water.
make sure there is no air in system.
if u removed belly pan, put that back on ASAP!

ZeroBanger

no its not losing coolant, the water pump is good. The belly pan is on.

The guys at this shop already put 50/50. I am so pissed now. They were just supposed to check out the car.

rxrotary2_7

is your temp sensor work right? are your fans actualy kicking on when they are programed to? are you running a stock based ecu? can you get full boost when this happens?
have you tested the temp at the thermo housing with a laser? does it read the same as you are saying?
is there anything interfering the signal? if so, try using an adjustable potentiometer inline with the signal and "trick it"

rxrotary2_7

maybe you should try some evans coolant if all else fails.

paw140

Check to make sure your temp gauge is reading correctly.

ZeroBanger

my power FC reads the temp and i can tell you its accurate. On saturday I could not get full boost. i had it set for .85, I got .73 max. In the morning when I run the car on the highway and the temps are a 87 C I get full boost easy. When my water temps are high, my intake temps are at 70 C+.

My fans work, both are new and the mechanics tested them today.

I'm at a loss.

ttb

take it to a different mechanic....

poss

iTrader: (5)

has anyone mentioned the thermostat??

ZeroBanger

well thanks, lol. they are currently working on it NOW as we speak.

ZeroBanger

they said its working. I was hoping that was the problem. they said it opens at 180 or something like that.

David

7-sins

Replace the thermo just to be safe. How old is your motor? A Mazda reman should have a new thermo in it.

Hmm you have a KOYO too.... I was about to say radiator. It probably wouldn't hurt to run some coolant system cleaner through. I used this prestone stuff, you wouldn't believe all the black crap that came out.

You sure the coolant fan relays are working properly? Make sure all the harnesses are plugged in and no wires are screwed up.

ZeroBanger

well the fans are running so I know they work. all the work has been done the last 5 months with the cooling system. engine is about 30K, thermostat was replaced then.

majikeye

test all of your relays asap! your fans may work but not be comming on soon enough. try driving with your parking lights on. i have been in the same position for about 6 months and one thing after another and it turned out the fans werent comming on at the right temp. turned on the parking lights one day and havent overheated since.

ZeroBanger

My fans come on at 93 C. I checked my temps at 92 they were not on, so i checked at 93 and they turned on.

thanks. I think the FD is cursed. It has to have some flaw. Some cars are perfect, but ugly, some are perfect but slow. Others handle like crap. FD's just overheat in 60 degree weather and ask nicely for a new engine.

David

Nathan Kwok

The mechanic has the right idea but I don't think he's fixing the right problem. Remember, while running a higher water/coolant ratio improves the thermal conductivity of your coolant, it also lowers the boiling point. Your boiling point is probably down to 240F under pressure, versus 270F with a 50/50 mix. If you are getting localized boiling, then at that point you will actually reduce your cooling ability and the problem will worsen. So, why do racers run straight water with water wetter? Because they have well sorted cooling systems and they know they won't ever boil over their coolant, and running straight water helps keep them in this good (180F-210F) range. However, your system still has a problem, by running more water, you are worsening it. You shrink your margin of error by running more water. I used to think running 70/30 or 75/25 was better, but I realized, if I'm not overheating and don't need to squeeze every little bit out of my cooling system, then its actually better to run 50/50, it provides more corrosion protection and reduces water pump cavitation at high rpms. Bottom line is, if you're still overheating, running even more water is NOT going to fix the problem. At this point I'm at a loss too, it seems like you replaced everything already. Bad caps maybe? You could have an internal clog in the coolant passages, but I've honestly never even heard of this. Also, 108C isn't too bad, that translates to 226F. This is getting into the danger zone, but the factory fans are supposed to come on at 221F and bump up to medium speed at 226F. However, if your fans are set to come on at 92C (198F), then the temps shouldn't go much above that. And they definitely shouldn't get up to 226F on the highway, even in 100 degree heat, as long as your moving. I would drive around with the 50/50 and see what happens first though.

majikeye

the fans should come on at about 220 or 230 F. im not sure what that is in C but i would check. see if all of the recalls have been done on your car. i think there was one for the cooling system.

majikeye

i have also noticed that the FD is an odly hard car to remove air bubbles from. much of the time if the mechanic has never worked on an rx7 he will not know how to do it properly. i usuall fill it up with the car off then put the cap back on, after that i squeeze the upper radiator hose a few times and then the coolant is low again. you will need to do this for about 10 min or until coolant stays at the top. this helped me out alot when i had my problem.

SPOautos

are both of the fans coming on??? Did you just listed or did you look at them?? I know a local guy that one of his fans was working and the other wasnt

STEPHEN

rynberg

David,

Are you SURE the fans are running the correct way and aren't running backwards?

I know how frustrated you're getting, I hope the problem is solved today. If not, maybe a trip to Sunnyvale is in order....

good luck

ttb

but the fans wouldn't all the sudden be running the wrong way....

rynberg

he just had new fans installed recently and has been having problems since.....you're probably right though, just trying to think of anything....

ttb

didn't realize he just had his fans done...in which case yea make sure it's turning the right way. i remember reading a post about that a while back.

ZeroBanger

I want to disable my A/C so I can have my fans run on my way home. I was told its a white clip near the fender? Anyone have a pic? Also, will removing the 15 A fuse do the same?