Cooks 7

I bought the Greddy front mount for my car about a year ago from Rx7.com. Ever since then I can't get my car to stop overheating. So far I have...
installed Koyo radiator...didn't help
switched to fluidyne radiator...didn't help
switched thermostat......didn't help
ran watter wetter with all above combinations.....didn't help
My next mod is on the way, going to install a bigger single oil cooler, mine is stock and beat up, but i am running out of ideas.
Is there no hope for 3rd gens with front mounts running normal temps. my car will overheat in 30 degree F. weather.
I mostly overheats on long drives at highway speed or after i turn it off, it never overheats at idle and not much in slow traffic....
any suggestions?????????????

vudoodoodoo

Radiator fan switch?

ttb

what do you exactly mean by overheat? you have a temp gauge? and btw, once you turn off the car the temp is going to rise regardless of if you have a fmic, smic, v mount...nothing is circulating and the temp will just go up and up.

Marshall

Something isn't right, check your fans and water pump.

gohorns

if its overheating at highway speeds where airflow is at its peak then your IC is probably leaking or is blocked

red 7

Is your A/C condensor in front of the radiator? Yry moving it underneath.
Do you have a duct between your FMIC and the radiator? The air could be going around the radiator if you dont have a duct to force the air through.
Just things ive tried with mine and I dont have any overheat probs (85-95C)I have greddy FMIC and koyo rad. stock thermostat, but the temps do go up after you shut the car off thats normal (100-110C)
I live in FL

apneablue

I have the FMIC two row and running it for a couple of days now...I like it mucho! as for the overheating, yes it does run a couple of °C higher than stock but not with the fans on...If you haven't already do the fan mod switch and it help a ton...As soon as I get some time I am working on a scoup idea to force air between the AC condensor and the Rad...Good luck.

Cooks 7

A description of my overheating is... stock temp gauge pegs itself all the way hot, coolant overflows through ast and into overflow until overflow is full and then spills out the top. it does this pretty much everytime i shut the car off. my fans work fine, it never overheats while i am sitting, only driving.

ptrhahn

iTrader: (9)

Your description doesn't make sense. Does it overheat while driving, sitting in traffic (engine on), or just puke coolant after you shut it off?

If its overheating while the car is moving, something is seriously wrong.

If its while sitting (engine on) then its likely that your fan(s) aren't coming on at the right time

If it pukes coolant after shutoff, the you have either bad o-rings and you're pressurizing your coolant, or the pressure cap on your AST is bad.

vudoodoodoo

Uh oh, sounds more like bad o-ring....

Cooks 7

Sorry about the confusion on description. I'll try again. It DOESN'T overheat when sitting, I can let it idle all day even with the A/C on and it won't overheat. It usually DOESN'T overheat when I am in traffic, stop and go, streetlights and then getting on it, ect. I DOES overheat when I am driving at about 50 or 60 in 6th gear, temp just gradually climbs until it starts puking. BUT, almost every time I shut the car off, even when it's been operating at normal temps. it heats up enought to puke coolant out of the overflow.

How do I know if I have a bad coolant o-ring? I don't get any oil or bubbles in my coolant in the water pump fill or the ast.

spoolage

iTrader: (2)

hah... time for a rebuild man... thats the symptom of a bad o-ring.

You might want to check for bubbles in the coolant filler neck, there are HUNDREDS of posts for 3rd gens on the how tow and this subject in gerneral... How often do you check your coolant levels, maybe you can catch it early and use a sealer. Does your exaust smell sweet/have a hint of a coolant smell.

spoolage

iTrader: (2)

hmmm... check for a white residue on the inside of the oil filler neck, take a white cloth and put it down the neck, it might be yellowish white I dunno... just hope the coolant isnt leaking into parts of the engine where it shouldent be !!!

Marshall

Man, is this another April fools???

....6th gear, stock temp guage pegged but it still runs, hmm.

Cooks 7

I wish it was an April Fools joke, but it's not.
I hardly ever drive the car now because when I don't figure I can overheat it forever and not have something happen...

mjw

iTrader: (1)

I am not sure this is a valid test, I have seen this on many cars including my own. I think the white residue has more to do with driving the car around like a grandma, it is just a build up of minor condensation. Taking the car out for a decent spin and winding the motor up a few times will clear this up, rotaries actually like this kind of treatment!

To answer the original post, the first thing I would try is blocking the airway path between the intercooler and radiator on the sides.. this will prevent the air from escaping around the edges of the radiator instead of going through it. I made templates w/cardboard and then cut my own out of thin metal sheets, if I am cruising on the freeway now the temp stays at 83C pretty much all the time. When you are in traffic you just use the fans anyway so it doesn't help much there. Your problem sounds worse than this simple fix though, get a test kit at the auto parts store to make sure you are not getting exhaust gasses in the coolant. Then you know it is an o-ring.

93BlackFD

bad o-ring

just my $.02

rxrotary2_7

it would most likely be one of the two depending on where the break in the seal is. if it is in the intake stroke, it would have different symtoms than on a compression or the exhaust stoke.

rxrotary2_7

its not. you are right. it is condensation...grandmom driving.

mb7

Hey I want a 6th gear 6th gear at 50?? I hardly take it out of 4th at 50 or 60. Also that must be like 1900 RPM.

SleepR1

Symptoms point to a failing coolant o-ring seal. FWIW, I have a GReddy Type 24 V-spec FMIC with Koyo--no cooling problems even on track. See sig for mods...

Trexthe3rd

I'm guessing you still have your radiator at the stock position. Many people with FMIC reposition the radiator to the upright position for better air flow at highway speeds.
First off, the temp rise caused by the lack of airflow should only cause slightly higher running temps at highway speeds, not all the way high on stock temp gauge. If the temp goes that high and causes coolant overflow, there is probably exhaust gas leaking through the water seal (most likely rebuild is necessary).

Now that's out of the way. Here's what I did to reduce the running temp with FMIC and stock radiator location.
1. The 5 blade fan is changed to the 4 blade for pulling more air throught the radiator. (Costs about 35.00)
2. Environment seals are used to seal off gaps around the radiator where air could escape. (Costs ~10.00)
3. The fan is controlled by a thermal switch to come on at 180F (Costs 45.00, but requires some wiring knowledge)
4. Custom made belly pan with larger and more aggressive ports to redirect more air to the radiator at high speeds (Costs 150.00).
The combination of theses 4 mods keeps my coolant temp at 178F (idle) and 190F (high speed).

RX-8

iTrader: (6)

i've had the exact same symtoms. turned out to be bad o-ring. so now i have a new reman. sorry, hope i'm wrong.

1FooknTiteFD

I don't think it has anything to do with the FMIC. I havea friend running a 3 row and he has no problems even on a road course needless to say it won't overheat on the street. Something is up with your car, you should get it checked out. Did these symptoms occur immediately after you installed the FMIC or was it pretty bad before and worse now? You should get a water temp guage and see what it reads. If it reads anything over 109 then it's overheating

Cooks 7

Sorry about the 6th gear quote. just wishful thinking. i checked again and i do have small bubbles in the water pump fill and immediately after it's started it smells like coolant just for a second. So... i guess i am screwed. what causes o-ring failure anyway, my motor has about 50,000 on it and has always been babied. the cooling problems did start right after hte front mount, i guess it could have been coincidence.

to answer another question, i mounted my radiator more upright for more air, like the greddy kit suggested.

any opinions on rebuilds or new motors? i have rebuilt motors before, but not rotaries...? who likes their rebuild the best???????