pyscho7

So I haven't had to drive further than 15 minutes this entire summer and my car has been OK. Its a 87' T2 with full exhuast, SAFC, intake, 720's and a few others. Recently ive had to drive to class everyday 45 minutes away. i have been running only water, but i threw a bottle of antifreeze in there because i figured it would help cool it. Well its been nothing but issues since. There is no leaks, no oil in the coolant, I have replaced the stock fan with an electric fan from autozone. and kept the fan shroud. i have it running to a switch with the AC fan when it warms up. i do not think it is supposed to be run but it pulls plenty of air. I put the thermostat in boiling water to see if it was bad and it was. I took it out completely and had to make a drive tonight on the interstate hoping it would be ok at 75 degree's outside. it was ok until i got on the interstate than it went up just over 3/4 of the temp gauge. i got off the interstate and it only dropped slightly. I bought a new thermostat and plan on putting it in tommorow after school. without the thermostat i can feel a steady flow of water, it felt like it was only about 1/3 of the top hose full. i keep trying to add coolant but the resivoir is full and it only takes a couple ounces of water. The hoses have pressure on them. Whats up with my cooling? i think the two fans should keep it atleast midway on the gauge, but 3/4's??? even when it was 100 outside it ran just over 3/4's. Oh yea, and i just put in 5 quarts of a full synthetic. I am really worried about warping the housings at this point and tommorow i have a spare vehicle but not for long. Any ideas????

misterstyx69

iTrader: (142)

Well using Coolant would be My suggestion.Water will corrode the Passages of the cooling system and could lead to Engine failure...using a 50/50 mix of coolant and a Bottle Of "Water Wetter"(brand name),that would Cool your engine down effectively,also getting New Thermostat,and Rad cap...Sorry,,now I am reading your Post again(but didn't want to erase the Info I just typed).You should Make sure that All the air is out of your Cooling system.Do not Depend on the overflow Bottle to bne used as a Filler location..meaning just addding coolant to that Bottle will not take the air out of your cooling system.Another thing I am thinking,is Are you Running this car with out a Skid plate.(plastic Belly pan that goes from the front of the car to cover the Bottom of teh engine from road Debris)?This Part is Functional as a Air Diverter and Keeps the air Going Through the radiator and fan and To the Engine,and not allowing the air to Fly all over the engine bay...so,Look up 'how to fill your cooling system Correctly",I think If you try Kevin Lander's site of www.rotaryresurrection.com ,hit tech and take a look,he should have something on cooling system filling...You have a Lot of Cash Tied up in this car(sounds like it anyhow),so Make sure that the fluids are always at their Peak Levels,so your engine won't Decide to take a dump on you out on the interstate.

pyscho7

appreciate it. I did put a new filler cap. Ive tried burping the system, but it was before i put the cap on today, Ive heard of the water wetter. kind of makes me mad they didnt stick a rad. cap on top of the radiator i think that would help keep air out of the system. I may buy an NA fc and swap radiators since it does have the cap on top also. it also has 130,000 miles less than mine does. I will read Kevin's site to double check everything. I paid $4500 for it and when i start having the cash from my new job starting september 5th, i have to buy tires, ceramic brake pads, and i will be building a new engine with a 60-1 trim turbo and will probably run it at about 15 psi, so that means new injectors, FMI, boost controller, and I will replace the clutch. so another probably close to $4500 which is what i paid for the car. Supposedly the engine had 40,000 miles on it. and ceramic seals, i dont know how true it is now and i wish i didn't have to rush into buying a car. which makes me kind of regret the car, but it purred at 700 rpms in the winter. now it sits at like 600. the compression has been 75 psi on the rear rotor and 85 on the front the last i checked. it still holds a idle, it just is not consistent it sits at 600 most of the time, can sit at 1050, or 750, just picks and chooses. i believe it has no vaccuum leaks, i think it has someting to do with the fact that theres a 3" dp after the turbo with no cats.

texFCturboII

iTrader: (17)

whoa, whoa, whoa, what is the power of that fan from autozone? CFM i mean? It may be waaaaaayyyyyy to puny to cool a rotary engine!!! You do not want to overheat these engines, that is BAD BAD BAD for the aluminum housings!!! If you want a cheap fix, go to the local junkyard, find an old pontiac grand am, 6000 or fiero and pull the e-fan off of one of those. Those crappy e-fan's they sell at autozone and O'reilly's and the like are just to weak to cool your car at idle!!!! You need at least 2500 CFM!!! Don't run the car without the thermostat either, that leads to overheating as well!

Slammedblk7

iTrader: (7)

You messed up when you put that electric fan on. Use either a fiero, taurus, or the black magic e-fans. anything else is questionable. If all else fails the stocker is the best cooling.

pyscho7

bought a 2 speed escort fan, working on currently. putting it all back together tonight, anyone know some good relays to use that are already on the car? i dont have a/c or power steering, previoius owner removed them, dont know if they have any relays yet. im still looking around.

texFCturboII

iTrader: (17)

Again, what is the CFM of that escort fan? Is it the same as the taurus (great fan to use) A rotary builds up alot more heat then a four banger escort! If you can, hook it up to the Water ThermoSWITCH. ( grey connector on the back of the waterpump housing) That is the circuit that turns on the stock auxilary e-fan when things get hot, it's a great way to keep things cool. BUT, make sure that fan is going to work to cool things down.

pyscho7

i used it from rotary ressurection's write up, its a 2 speed electric fan, i got it on 2 seperate relays, with a dual control switch. when its below 85 degree's its been great. i keep it on the low setting and i havent had to turn on the high mode yet. its, when its about 100 outside it runs about halfway on the interstate. i believe i dont have anymore air bubbles in the system, it should have more than enough cfm, it pulls air so hard through the radiator it makes my little ac fan spin. and it sits on the opposite side of the radiator from the main fan. Only issue i can think of now is the fact that i am not running a shield underneath the car(bought it like this) i am going to buy one shortly, or if anyone has one i'd pay em. i will try the for sale section. Any other thoughts?

texFCturboII

iTrader: (17)

That shield being there or not being there isn't going to prevent the car from overheating. Are you still using the stock radiator? Maybe it's time to switch to a Koyo or Griffin, something bigger and aluminum!

jackhild59

iTrader: (7)

It sounds like you are nearly fixed. Just get a belly pan as soon as you can. There is also a deflector between the front bumper and the radiator that ducts air into the front of the radiator. This is another necessary item for cooling on the highway. There lots of info on the forum that says the belly pan is a major factor in cooling the car at highway speed.

Don't spend major bucks on cooling upgrades like an all aluminum radiator until you restore the under tray and radiator ducts. You don't need that fancy rad until you really need it.

Good luck!

jackhild59

iTrader: (7)

I am interested in this. So, you left the STOCK shroud, removed the belt driven fan, then installed the efan into the stock shroud?

?Sounds kind of interesting. Any pics?

ericgrau

iTrader: (1)

1. Water will rust and corrode. You must add antifreeze. Plus, even though water cools better it boils easier, which defeats the purpose of lower temps. Use distilled water if your tap water is hard, or you'll slowly build up sediment in your cooling system. Hard water leaves scale on your bathtub spout, etc.

2. Replace your thermostat. It's the #1 cause. If problem comes back in a month, replace it again, b/c aftermarket thermostats suck. Really just order an OEM one as soon as you can. Try a Mazda dealer or www.rx7.com. Other '7 sites might have them too.

3. I wouldn't recommend it, but you could run at 3/4 on the temp gauge for several months in a row without any serious problems. I know b/c I used to have a... well, worse RX-7. But if you start to overheat you must pullover immediately.

4. Full synthetic won't help significantly.

5. Easiest and most effective way to get air out of your system is the Lisle funnel (forum search to see how awesome yet simple it is, google search to buy one). Simply running with the rad cap off and pouring coolant in, pulsing hoses, etc. will not be nearly as effective nor quick, no matter how careful you are. Air in the system will make the temp move around and probably raise somewhat, but probably not as bad as what you're experiencing.

6. Water wetter will lower temps a tiny bit, but isn't that effective. Fix your cooling system first.

7. You only need an e-fan if your stock fan is bad. If your stock fan is bad, you will have problems at low speeds and stops, but not on the freeway. Also a good stock fan (really the fan clutch) will feel like it's full of peanut butter when you try to turn it. A bad one will be much looser. An e-fan is almost certainly weaker than the stock fan (if not broken), so get an extra beefy one if you get one.

8. The plastic undertray, foam around the radiator, etc. will help somewhat. But if you are running that hot, you have a problem that needs fixing.

9. Only get a bigger radiator if you have significant power upgrades. Again, fix the problem first. Even if you are upgraded, a simple commute should not make you run hot.

Other much less likely causes are a bad water pump and a clogged radiator. Check the thermostat, check the fan, and get the air out of the system first.

bbonga

If you can't seem to get the air out of the water, the problem could be a blown gasket. Compressed air/exhaust is leaking from the combustion chamber in to the water channel. Have a look at my thread here to see if you have the same sympthoms: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/coolant-problem-542266/
I rebuilt the engine and the problem is gone. I could even see where the gasket was broken.

AUGieDogie

iTrader: (4)

Are you filling it using the air bleed in the rad neck?

https://www.rx7club.com/2nd-gen-archive-72/filling-coolant-after-rebuild-383818/