deprato07

hey everyone. so i jsut bout a 87 rx7 turbo II and my coolant wasn't running through the car, it was all goin to my overflow and spilling out. on top of that i wasn't getting any heat and my temp guaging was climbing fast. so i changed the thermostat in hopes that it was that simple. but it jsut did the same thing on me... mayeb the same thing has happened to somone else.. plz help. and PLEASE tell me i dont need a rebuild!!! thanks

Turbo23

iTrader: (4)

one way to check your thermostat, Put it in a pot of water with a thermomter. Boil the water, when it gets to like 180, you should be able to see it open. Also make sure you get a mazda thermo. The ones from like autozone, discount auto parts, etc are junk.

HAILERS

Leave the thermostat out all together. Then if the coolant dumps out the overflow............buy a new radiator cap, if it still dumps out............rebuild the engine.

Turbo23

iTrader: (4)

rebuild anyways Its fun

deprato07

thahnks. im guna go see what it does when i leave the thermo out rihgt now. my dad called a mechanic friend of his and he said that it could be a head gasket. stupid question, but im new to rotory.. does a rotory motor have a head gasket?? thansk for your imput

trainwreck517

iTrader: (1)

No head gasket, but it does have water seals. Does it smoke at all when you turn on the engine? Have you replced the radiator cap?

CoRDiTe

leave the thermostat in it. Thermostat is in it for a reason. Your injectors start to work correctly at a certain temp. If you have the thermostat out of the car and run the car like that you can damage your injectors.

deprato07

i just took the rad cap out to see how it worked without it . and unfortunatly it worked more or less fine. but u say change the rad cap... what does that have to do wiht nething??? and do the water seals do basically the same thing as a head gasket?

deprato07

opops. i said i took the rad cap out. i ment to say i took the thermostat out

deadRX7Conv

If you don't have NEW OEM thermostat and rad cap, assuming anything else is a waste. I had a bad rad cap that caused a ton of my coolant to exit into the bottle. A defective thermostat will cause overheating along with a rush of 'boiled coolant' out of the engine.
You should also be using a 50:50 blend and NOT just topping off with straight tap water.
And, as the vehicle warms up, you need to make sure that the fan isn't 'free wheeling'.

Those parts are cheap and you can keep them for the rebuild if your coolant seals are bad!

Icemark

Do not drive with a thermostat or restrictor plate, the engine will spot overheat and the water pump will caviatate causeing more cooling problems.

If the rad cap is bad, it will not allow the coolant pressure to build up causing reduced coolant cooling, and coolant will escape into the overflow.

If a water seal is bad, coolant typically leaks in the combustion chambers, or combustion escapes into the coolant, forcing its way out through the overflow.


And as mentioned above do not use anything but OEM thermostats or rad caps.

Sideways7

iTrader: (7)

Does it have ***** smoke on startup? If so, you might have bad coolant seals. Take off the rad cap and see if the coolant bubbles out. If so, thats usually a sign of bad coolant seals.

deprato07

so i think i might try to get a new rad cap and see if that changes it. i never knew that something that is that simple could do so much. my dad is bring it to a mechanic tomrow and im praying that it wont need a rebuild caus if it does i jsut simply cant afford it and will have to get rid of it.. but im guna check the rad cap first, wiht the thermostat in and see how she works. thanks alot for all the imput. o im also not getting ne heat inside my vehicle, could this be ebcause of the rad cap and coolant problem aswell? or could it be someting like a heater core?

Ambassador90

I am having the sme problem with my S5 n/a.
I first thought of the Thermoastat, and found that the privous owner didn't have one in it.
Next, I thought of the water pump (almost all of my knowlege is piston based), then I started reading the posts on the coolnt seals and got a little scared that I would be facing a rebuild.
3 Mechanics (1 familiar with rotaries) said to replace the water pump - 90% probability.
I did - problem remains.

---deprato07,
Does this happen at idle (overheat and coolant loss via reservoir), or only when the engine under a load? (mine only overheats and empties coolant when under a load, and starts cooling when the vehicle is stopped an idling)
Also, is there an extreme pressure build up in the upper radiator hose when this happens?

deprato07

no mine does it at idle, but my car idles at around 1250rpm or so.. i think thats a bit higher than the factory setting. im the same way where most of what i know is from a piston motor whicch is why i came here for most of my stuff.. ill check that waterpump idea. thanks

Icemark

yeah, almost double what it is supposed to be.

And it won't be the water pump if coolant is being pushed out... don't waste your time.

Ambassador90

Icemark,
do you think I should try the radiator cap, or am I stuck with a rebuild?

Icemark

As mentioned by Hailers, a new OEM rad cap is pretty cheap, and would tell you for sure, but it sounds like both you and deprato07 need to rebuild your motors.

Spark plug condition, and a compression check would tell for sure if you need to rebuild.

Either way, a new OEM rad cap is always good to have if you are rebuilding a motor anyway.

Ambassador90

I had a chat with my supervisor today. He stated that the exact same thing was happening to one of his older Honda's:
Upper hose swells
Coolant loss through resivoir
Lower hose empty
Idle cools down temp
Blowing in upper hose pushes coolant through the system

His was a radiator that was nearly clogged. He thinks that is probably what my problem is.

Any thoughts?

CoRDiTe

you should be idling at 740-900 rpms idle. 740 is factory setting. Even though you can idle up to 1200 fine but I wouldn't recomend it. 1000 should be the highest at idle with no mods.

deprato07

i was talkin to my boss and he said that it could be that my rad is blocked? would this be a possibility??

Icemark

doubtfull

Ambassador90

Well, yesterday, I flushed the radiator...it didn't work.
It really makes no sense to me how this is happening:
At normal operating temp, I can rev and hold it at 4,500 rpm and it doesn't overheat (it actual starts cooling off).
But if I go driving and keep it under, it does overheat whether I rev it up or keep the rpm's low.
No coolant in the oil or exhaust. No oil or gasoline sent in the coolant.
And it really looks like the raditor is restricting the flow because the lower hose will barely have anything in it while the upper is under extreme pressure and full of coolant.

The only thing I didn't do was replace the radiator itself. And I can't afford to do it, if that doesn't fixt the problem because then I won't have enough money to get an other car.

I don't have the time, money, or facility to do an engine rebuild, so I think I'm going to scrap it and go back to piston engines.

--deprato07,
I wish you the best of luck.

WARX7Pwndme

Similiar Situation, but I might be able to provide more info.
1986 RX7 GXL FI -148,000 miles
I had just finished un----ing what Autozone and a good friend had done in my tune-up,
Which involved correcting the idol, readjusting the TPS, buying a new alternator, putting in a fuel cut off switch, buying the mazda workshop manual, etc etc... hell of a time right?
Well I just had it all fixed and driving smoothly, but yesterday I was driving to a local car parts store to buy new battery terminals when I was about half way there when the add coolant buzzer and light alerted me and coolant started spraying everywhere, I parked it and saw that the resevior was full to the top and the rad cap was turned about 30 degrees open. I added some coolant in, not knowning what do to and tried to drive it and it overheated immediately, I'm talking maybe a quarter mile, and it was to the hottest point of the dash thermometer and the coolant was making my engine smoke under the hood, so I stopped immediately and used the heater trick to get it back home (good drivers ed taught me something video games didn't) when I got it home my step dad and I were back into troubleshooting mode and we checked the coolant tubes on the upper and lower half of the radiator and they were completely cold, so we opened it up and it's like there wasnt any coolant in there at all(regardless of what I put in before and it being pull before the trip) we filled it agian and put it back together and it took about a minute to max out the heat just as his regardless of the rpms or stress, we tested the 192 degree thermo on it and it seemed to work flawlessly, we took of the water pump but it seemed to work fine, regardless I bought new water pump and 195 degree thermo and we are putting them on tomorrow and testing the rad cap. I don't believe the radiator is a factor because of the cold tubes. No coolant is in the oil or the exhaust. Nothing is left where the coolant is suppose to be. It feels like I've had to replace about half the engine in the last month, any one think it could be anything other then the rad cap or water seals?

KompressorLOgic

iTrader: (6)

thats the most BS ive ever heard, lets see ive put over 30K on my car with no thermostat with out any problems!