Hey everyone

ive been having an issue and cant figure it out.. my car is running alittle on the hot side, my PFC reads temps 91 - 102 degrees C, the average temp is around 96C-99C, ive done several cooling mods ....i did the AST elimination mod, koyo rad. new rad. tubes and im using prestone 50/50 ORANGE coolant with water-wetter. i still have the under panel on but i just dont understand why she's running on the hot side. NOW.....HERES A BIGGER PROBLEM WHICH I DONT GET, when i did the ast elimination mod i know you need the 86 rx-7 rad cap neck with the nipple on it to run to the overflow tank....., ok i got it, but when the car is running for about 30-40 mins...coolants starts leaking out of the overflow tank. ( i checked it and its not broken ) and its not over filled i have it at the F on the dip stick. why is it leaking through there? i have pics so you guys can see what i have...thanks in advance

 

Sounds normal for NJ / NY running that IC and rad setup. My car had the same setup and ran those temps when i lived in NY.

 

what about the leaking coolant issue?

 

I thought we were supposed to use green coolant only. I've also been told that water wetter is a no no since it might corrode some parts.

I live in NJ to and on the highway I typically run at 86 tops. I hit 94 in bad traffic though. My fans turn on at 95 deg. Your temps do seem rather high.

 

Read the cooling system thread in the FAQ for that. Too much info for me to repost.

 

orange coolant is bad?

 

The "leaking" coolant could be a result of the radiator cap not holding the correct pressure in the system. This results in more coolant than normal being pushed out to the overflow as the system temperature increases, filling up the overflow container, causing it to...well....overflow. Have it tested or replace it.

 

What psi cap are you running? Try running a 16 psi cap. Maybe the one you have is worn out. This will also raise the temperature at which the coolant boils which will give the engine more protection. Also you might have air trapped in the system which so take some time to propely burp the system and check it over a few days.

 

ok i'll swap out the cap today and let you guys know...but should i change my coolant to the green stuff and not the orange?

 

change your coolant and run a mix of like 80water/20 coolant, you dont need that much coolant, if your area get really cold during the winter (snow/freezing) then run like a 75/20, i run like 80-85% water here in az

 

I run 50/50 and that seems fine for my uses but I don't drive very aggresively either.

I heard 80/20 before as well but everyone I asked said 50/50 should be sufficient for my purposes but I don't live in a very hot area.

I wish I could tell you what to do about the coolant but all I know is that I've been advised to use green only and I have read that you should run green only. Im not sure what the process of changing the coolant is though. I hope its not to complicated.

 

I hope you have a front under tray? Without one your fighting a loosing battle, the air will never reach the radiator.

Since you have a FMIC, I would suggest you do some duct work and try to seal the area below and on the sides between your FMIC and the radiator. This will help force the air through the radiator. I have a similar set up and I run my fans all the time when the car is running. We just hard wired the fans to the stock fog light switch.

With the FMIC you are a little screwed when it comes to temperatures when you are stationary. The car really needs to be moving for it to be an effective setup.

On another note, I wouldn’t use the water wetter; I have seen some seals that it crystallizes on. I use 60% distilled water and 40% coolant.

Normal temps: 82-84 On a hot day in traffic: 85-87

 

Nice temps man.

 

yea i have the under tray on...what do you mean by some ducting work? can i see a pic of your set up? you said u have one similar to mine

 

https://www.rx7club.com/showpost.php...20&postcount=9

 

We get a mean winter and a short summer up here. I only run 50/50 in any of my cars.

 

O no, now Im wondering if I should use a different coolant/water ratio. I wish I wasnt so lazy and that I could do the mixing myself. What a shame. Do you know of places offer any other mixes besides 50/50? I havent seen any other type.

 

tmoney, it looks like we have the same setup as well. fmic, greddy intake, i have a koyo rad, can't tell on yours... anyway, what are your air charge temps like? mine can get up to 50C+ on hot days. i'm making a cooling plate tonight like the one pictured earlier. i'll post some pics when i'm finished.

looking for a way to keep the intake temps down though...

 

at night my temps is 29-37....during a hot day its reaches up to 78 degrees : ( when you make that plate send me pics...i may want one too, also post pics of your engine bay : )

 

UGH!!!! this is a ******* NIGHTMARE!!!

ok so i changed the cap ( 16 psi ) and i swapped out the orange coolant to the green stuff ( prestone 50/50 ) but i added distilled water to it, bout another jugs worth to it, idk i read somewhere saying that water is the best heat absorber esp. mixed with coolant. but anyways i did that and sucked all the air bubbles out with my lesile funnel...i even went as far as doing some ducting work to help air flow... the car ran beautiful temps read 89degrees C which was a big improvement from my usual high temps...

now..Tonight after driving for about 40 mins i noticed that temps when up to 101...hoping it would go down i popped it in neutral and rolled on the road but it only went up. i stopped ( engine off ) and i noticed a bubbling noise from my over flow tank and coolant leaking out from the bottom of it..and i heard my buzzing sound from my dash saying to add coolant, as crazy as i am screwed off the cap and water shot up after 30 seconds after it was opened ( i kno i kno never do that shame on me )


what do you guys think is my problem? i was going to change my water pump gasket do you that that will help? this is driving me nuts!!!

thanks

 

It sounds like you should turn your a/c on to turn the fans on to see if that helps. If it does then you can always do a fan mod so you can keep them running all the time. As far as the distilled water its not so much that its better for cooling but its pure water so it wont get nasty and it will help keep your coolant system clean. When you changed out the coolant did you get it flushed?

 

your electric fans are working right?? if you could get ahold of a datalgit to adjust the fan speeds to around 86C that would help alot. but with all your cooling mods it doesnt seem like you should be having the issues you are. especially if you werent driving around hard for 40 minutes.

 

Why in green hell would you think changing the water pump gasket would do ANYTHING?

I am sure you don't want to go here but....it sounds possible that you have the beginnings of 'O' ring failure and you cooling system is simply being pressurized by exhaust gases.

But you certainly need to make sure your fans ARE coming on, first of all.

And, there still seems to be a contingent out there that keeps forgetting 'antifreeze' isn't just for keeping coolant from freezing, it is to keep it from BOILING also. A proper mixture (55/45 or 50/50) will put your boiling temp up around 225 degrees, if you go to 70% glycol your boiling temp gets closer to 240 degrees.
Coolant that isn't boiling isn't expanding (as much) and won't be going out your overflow and then causing a REAL problem with overheating, which is self-sustaining and self-propagating.

Personally, I suspect 'O' ring failure.

 

How's the T-stat?

 

where are the o rings