shotcallerx7

Maybe its because I live in Florida or my car is cursed. I've always heard the rumors of cooling problems with FMIC, but it was always from people that didn't own them, so I threw their opinons out the window. At first I had the stock rad with greddy FMIC and during the spring I didn't have any problems. Now that it is summer I couldn't drive my car longer than 30 minutes or I'd be on the side of the road. So I bought the Koyo rad and installed it about a week ago. Looks awesome, but now I can drive about an hour before overheating. Sort of a fix......but not really. Yesterday I hot wired the cooling fans so that the are on all the time and go full blast no matter what I do in the car. This helped more than the rad did. But if I have the ac on it over heats still over a bit of time. This is the interesting thing about this Koyo, If I'm driving in town and temps are 92-95 celcius (according to the FC commander) stop to get gas or whatever and shut the car off for a few minutes, turn it back on and FC says 125 Celcius and the temp gauge in the car is almost to the H. If I did that with the stock rad in the past the highest I ever saw was 115 C. So this thing retains heat like nobodys business. Once its at 125 it will not go below 105 even after you drive around a little while. I'm like WTF, it wasn't hot when I shut it off, now it is. Since I just did this fan mod yesterday I still have some testing to do, but I probably won't work. I'll do anything to fix this problem. I'm not sure if the reason for this post is to warn or to ask for answers and suggestions. I'm just going crazy over this ****

mjw

iTrader: (1)

Well first off I would make absolutely sure that everything in your cooling system is working properly (caps, AST, no leaks, fans working etc.) and make absolutely 100% sure that there is no air in the system. I have a feeling that something is not working up to par, I have a blitz fmic myself and I know it is thicker than the Greddy 2-row.. I haven't had any overheating problems in So. Cal and the car has seen 100degree heat.

That being said there are a couple things that may help you out.

1. If you remove the underbelly pan and look at the edges of the radiator you can see that there are pathways for air entering the front air dam to escape around the edges. This is what happens much of the time, especially at higher freeway speeds, air will take the path of least resistance. To remedy this fabricate some block off plates around the edges, or infill the gaps with something hi-temp. This will force all the air coming in to go -through- the radiator rather than around it.

2. Make sure your underbelly pan is mounted well and seals the underside of the radiator off.

3. Be selective about when you run the A/C.

I have seen a temp increase across the board with the fmic, not anything drastic though. Around town I am never in danger of overheating because I can switch on the fans at will, even in 90-100 degree heat my water temps stay below 90C. On the freeway I had more trouble because air was escaping around the edges of the radiator, my temps would climb very slowly on a hot day.. especially if the car was under a lot of load.. like when climbing a hill. Sealing the edges solved this and decreased my overall temps. HTH

Matt
93 SSM

kempo

iTrader: (2)

check your thermostat

Blackbeast

I doubt FMIC was the problem. Maybe some of the things in your cooling system isn't working properly and slowly evident itself now that it's summer time.

We have had many FMIC with aftermarket radiator in SoCal and none has any over heating issues. However, most of them either has the fan mod done to turn on the fan on at will or they have their PFC turned on the fan at 80 deg C.

As for the Koyo that shows very high temp when car is off, mine does the same thing. However, once I get on the road, temp will drop drastically to about 87 deg C. It is normal that the coolant temp rise when you shut off the car, that is because your radiator is not getting any more air flow, and when you park your car, your cooling system gets heat soaked from the motor. Not sure how high mine gets to but I would think 120 deg is way too high, something is definitely wrong with your cooling system if that's the case, my needle with the KOYO never moves if any.

I have also heard numerous overheating will deterioate our weak rotary water seals, perhaps yours is on its way out.

Timmy

mjw

iTrader: (1)

I agree with Kempo, check your thermostat as well. I have also noticed that my water temps are high when I go to restart the car soon after I have shut it off, but this is normal..Timmy explained why pretty well. One thing I do is most often when this happens you are just making a quick stop, going into the market or something and right back to the car. When I am in this situation I just leave the fans on while I am in the store, when I come back out my water temps are in the 80s and the car is much happier.

Matt

lane_change

iTrader: (20)

When I installed my Blitz FMIC I had horrible overheating problems for the first few days where as I could not even start the car or it would climb like hell up to 114'C. I replaced the Thermostat and I checked my lines and found a kink in my AST - Overflow tank line which was not allowing in extra coolant as needed which made my car overheat. I fixed those problems and it works perfect now. Never above 90'C while cruising around and never above 95'C after drag racing.
When I shut the car down though and then turn the ignition back on to watch the PFC temps, they climb up to around 106'C and then slowly go back down. Definately check all your lines and caps and I would replace the thermostat as well. It is simple as pie to replace and is also not very expensive. Safety first.

7 eleven

I'm seeing outside temps in the 90's here and my coolant use to do the slow crawl up to 100c(read off my commander) so then I cut the undertray in a 6" by 24" box right after the FMIC(I have a XS FMIC so it's close to the front) and fabed a a plastic scoop to direct the air into the rad. Now I never seen above 93c even after beating on it in the heat(I had to see how well it worked) I did this after I tried to thin out my coolant 20/80 and added waterwetter. Also I have my PFC turn the fans on at 90c. I think this mod hurt the air flow thur the IC due to the high pressure behind it, but when it's cooler out i'll just cover the hole till next summer. I'd rather lose a few hp than over heat it.
good luck

darkside7

iTrader: (12)

what is your coolant/water mixture??? try putting some waterwetter. Also, put in a real temp. guage. i know this becuse my pfc temp readings were 10c off from my greddy temp guage.

CCarlisi

7 eleven

Good post re the vent. I'm still trying to decide between the 2 row Greddy and the M2 race. I was thinking of doing the same thing you did but was told by a few people that it is a low pressure zone so it wouldn't be effective. Does your duct extend below the belly pan or just flush with it? I'm wondering if the former would be enough to generate positive pressure in front of the rad. If not maybe the low pressure below the car is helping to pull the hot air out of the engine compartment(and the front of the rad) thereby dropping the temps.

Thanks for the info

-Chris C.

Blackbeast

Yes, Greddy has its own sender, and you can even buy the water hose adapter where the sender will plug right in. All you have to do is cut the upper coolant hose in half and connect the adapter with hose clamps.

Timmy

Dimcorner

I have a FMIC and I live in Miami.

My temps on HWY will not pass 96 on the hottest day.
It will go up to 96, then drop down to like 92-91.

Right after a hard pull it might jump to 100, but that's it.

I have a fluydine radiator, no fan mods.

jspecracer7

Try loosening your Alternator belt a little bit. I noticed that when I tightened mine down a lot, that my water temps were 5 to 10 celsius higher than if I loosened it....seriously...

Also, if you've got the PFC, go find someone with the datalogit equipment so you can turn your fans down...It may cost $260 or so, but it's SO worth it.

lovemyseven

iTrader: (2)

awesome post! this fits my situation to a tee! First of all, I heard that the PFC is getting it's reading from the sensor behind the water pump and is usually 10c higher, which is what darkside 7 said. I did all of the same things. Maybe I need to add some type of block off material to the sides of my koyo radiator. Does anyone have any ideas for this? With the a/c condensor being in between my fmic and the radiator, I have been experiencing some condensor heat soak and the a/c doesn't work very well in traffic. I am going to add a fan to the front of the a/c condensor.

jspecracer7

I used packaging foam to block off the sides/top off the radiator. Mine doesn't melt and is shoved between the radiator and the fmic.

Fd3BOOST

iTrader: (7)

To late for me. My coolant seals are leaking now. I'll be takong the car off the road in 2 months when the tahs expire. It won't see pavement again till next spring... Heat soak killed my coolant seals....Pooo Pooo

jspecracer7

If it's the coolant seals that killed your motor, then take the engine apart, go buy mazda part # N318-10-S60A(O-ring Kit), N390-10-502(Front Cover Gasket), N386-15-162(H20 Pump housing Gasket) and rebuild the focker! At least the engine's not "blown" i.e. cracked apex/corner...that usually takes out a rotor housing

Of course, you'll still have to check to see if the engine's good i.e. no warped engine parts.

Fd3BOOST

iTrader: (7)

Yes actually I have been steady reading like a crazy Focker trying to get prepaired for this. I will mnost likely get a reman. But would rather do the rebuild my self for obvious reasons. Last night I was thinking that I need to find the info on how to precisely check the rotor housings for warpage. Do you know of any good info site that I don't already know of jspecracer7? If I do the rebuild myself. I sure as **** am not putting back in the stock o-rings. I'll get Haynes o-rings that are more durable against heat soak. Also I was redaing about a tiny metal heat shield that sits in the small groove w/ the o-rings to keep the combustion and coolant heat from destroying them.
All I know is my next setup is going to be modded to run as cold as I can Focking get it!!

jspecracer7

Seriously....the stock O rings are fine. I've talked to many people running well into the 500 +rwhp and they have convinced me to not buy anything other than stock o-rings.

The PFC with datalogit is GREAT for turning the fans on at a lower temp. The Haltech can do it as well. That's how you get your temps down. Also using an aftermarket radiator. I truly believe that you can run a FMIC in Okinawa's 95+ ambient air temp and still keep your car cool. My water temps never get past 90 Celsius, even after a few hard runs...and I still have the stock radiator.

7 eleven

Ya my scoop goes slightly lower than the lip(I have a r-1)

cdk 4219

Try some redline water wetter, or a 70 % 20 % antifreeze water mixture. Ethelene glycol isnt the best heat transfer medium. A good coolant flush would be good too.

1FooknTiteFD

try lookig at your bearings on your water pump. If that part goes bad you will have heating problems. Also look at your stock temparature guage. If it is truly 115 degrees celcius, then the needle will move above the middle (it moves at 110). If the stock needle doesnt' move then don't worry at all. Like most people say, the power fc water temp guage is highly inaccurate. I have both greddy water temp guage and power fc, and the greddy one is more consistent and accurate a the pfc always shows noticibly higher water temps.

SleepR1

How do you know your coolant O-rings have failed?

The last time I had my car at the track (Nov 9 2002, ambient temp was 55 F), the overflow reservoir was overflowing coolant after each track session. I run the heater to help cool the motor during track sessions. On the road the coolant was fine. I thought that was wierd, when the overflow reservoir was overflowing coolant after each session though...

Mr rx-7 tt

iTrader: (5)

The o-rings have nothing to do with hp...The stock o-rings are failure prone and are one of the main reasons for engine failure. Replace them with aftermarket ones, problem solved.

Mr rx-7 tt

iTrader: (5)

Water wetter eats the stock o-rings.