gus5891

i have 87 mazda rx7 non turbo i blew a heater hose last night an could not get on from auto zone so i capped it off to make it home i am now pretty sure i was not supposed to do this. now i have replaced the hose but the car wont stop overheating an the buzzer keeps going off. when running the motor sounds fine but i have never owned one of these before an i dont know how to fix it. if anybody here can give me any advice it would be much appeciated.

Black Knight RX7 FC3S

iTrader: (7)

did you replace the coolant that leaked out????

gus5891

yes i did. so far i have repalced the thermostat & refilled the car with coolant. but i really dont know what all to do

calrx7

did u refill the coolant correctly?

Boostmaniac

yeah, bleed the coolant system first. If it keeps overheating you have either cooked the motor or are going to cook the motor. That means rebuild time.

-Maniac

gus5891

would you refill it the same as any other car or is an rx7 different like this. the reserve is full an i took the cap off thats by the thermostat an filled it up there. one of the things its doing its been blowing air into the resovior an bubbling up when i removed the hose from by the radiator cap that goes to the resivior it started blowing steam out from there

gus5891

but there is one issue if i keep it at high rpms it doesnt overheat it just sits at the same temp but the buzzer never shuts up

gus5891

how exactly do i bleed the coolant system?

spiderx7

i recentlly had a similar exp but it was the top rad hose .then once home the freaking beeper kept buzzing but the temp did not rise.i thought dam the engine is shot.wrong she was still low on coolant/distilled water.fill with the car on and warmed up tru the rad.make sure the bubbles are gone before closining the cap.

stevej88na

Bubbles in the coolant will do that. They can get caught at the water pump and pretty much stop coolant circulation. Sometimes you can get them out of there by removing the top cap and squeezing the radiator hose to get oscillations going in the coolant lines.

SpooledupRacing

ok here is what I would go over one more time.

check all hoses for leaks
replace the thermostat with a OEM (dealer) thermostat
replace the radiator cap (again with a OEM or a higher pressure cap)
make sure u use standard GREEN coolant with a 50/50 or 30/70 (coolant to water) mix


now on my car when I woudl have to do with the stock radiator etc is pull the neck cap off, and right where the radiator hose (upper) connects to the radiator there is a big screw on the neck on the radiator, u have to pull that screw out and then fill the neck with yoru coolant mix untill the coolant comes out that screw (pour slowly so u dont power feed the coolant out that hole)

once the mix comes out of that hole put the screw back in then top off the system.

start the car and turn the heat on full blast with the radiator cap off and fill untill it is to the top. Then u will put the cap on and turn the heater on full blast (defrost) now let the car run for 10 minutes keeping an eye on the gauge after roughly 5-10 minutes slowly pull the radiator cap off (be carefull it dont spray back at you, as long as there are no problems and the car is running it should not spray out it shoudl be at the correct level and u should be fine. one the cap is off then top off the system at the neck and then put the cap back on.

turn the car off and add STRAIT WATER to the overflow (to the minimum level) and then start the car up and go for a drive. get it up to temp drive it for a good 10 minutes or more going through the rps etc.. If there are no problems then u should be fine. then in the morning before u start the car pull the radiator cap off and make sure the level is full or top off..

one thing to know DURING the whole time have NO fluid in the overflow UNTILL I stated to add water. this will help to bleed the system and watch for any problems if u start pushing lots of coolant etc into the bottle and then it bubbles or (volcanic action)

I know this was long and I hope it helps!

gus5891

thank you all i will get to work on it tomorrow i very much appeciate all of your help

Richter12x2

iTrader: (1)

Did you all miss this? If the engine does this pretty quickly after startup, then that's usually a sign of a blown coolant seal, which tends to happen if an older motor gets really overheated.

Mine exhibited no other blown coolant seal symptoms (like smoke in the exhaust) but this and I had blown coolant seals on two separate irons.

Test it further, do a search on blown coolant seals and they'll have some checks. One thing I did was use a pair of vicegrips to clamp the line going from the radiator cap to the overflow bottle, and it didn't go to overheat immediately anymore, but it's dangerous to drive it that way, because as the heat and pressure build up you can do severe damage to your engine, and blow hoses wide open.

I hope it's not a blown coolant seal for you, but if it is and your engine was running decently before, coolant seals are about $80 from Mazda, so if you reuse your apex seals and don't have the $1000 for a full rebuild, you should be able to rebuild the engine yourself for less than $300. It's not as complicated as it sounds, and the best words of advice are, if you're not sure you did it right, do it again and MAKE sure. Otherwise you'll be tearing it back apart.

gus5891

well i bleed the coolant system as yall said to do an it ran fine for about 1 mile an started sayin add coolant so i bled it again and its doin fine now. I really want to thank all of you yall really know your stuff about these cars. Thank you all very much. One small question i'm being told that if i try to put a turbo on an rx7 that did not come with one i will blow it up they are tellin me the rotors are to heavy.does any body here know if this is true cause i dont know

ericgrau

iTrader: (1)

I'd worry about testing your coolant seals first. Overheating a rotary or not getting enough coolant will kill it quick. In the future I'd get a tow truck to bring you home. In the meantime, the guys here posted some good tips.

You can turbo an N/A it but it takes quite a bit of work. Do a search to find out how. The engine on the N/A does have higher compression than the engine on the turbo, so maybe you can't boost it as much before things break.

Richter12x2

iTrader: (1)

Several people have added a turbo to a rotary that didn't have one - the ones I remember off the top of my head are Aaron Cake and SonicRat - plus I know there's more. I've actually got a turbo sitting on the shelf for when I've got the huevos to try it out.

In the meantime I'm adding other mods little by little as money allows so that I can safely bolt the turbo on and go. I've got a boost gauge coming in next week (which will be a little silly until I actually get a turbo to go on it , I'm thinking maybe I can hook it up to my o2 sensor or something in the meantime so it will move around and stuff) and an aftermarket oil pressure gauge, an oil pedestal adapter so I can tie into it for the oil supply for the turbo, and I've already got the SAFC installed.

Since I just rebuilt the engine though, I'm going to run it a couple of months until I can be sure the car isn't going to go nuts just on pure principle before I start giving it reasons to.

gus5891

thanks for that info. but im still havin problems fightin overheatin. the new issues im havin are one the heater is actually blowin cold air out an two it keeps filling the overflow bottle up with water. once i bleed the system it runs fine i go for a ride get about ten minutes into it an the buzzer goes off again but the temp is sittin at normal. about five minutes later the temp starts to rise the first time its does it will heat up to about 3 quarter of the way an cool back off then about 2 minutes later it goes up the second time an you gotta shut it off

VacavilleFC

your motor is gonna be toast, don't drive it at all if it's going over half


gauge sitting at 1/4 = normal

gauge moving to 1/2 = REALLY BAD

gauge going to 3/4 to 4/4 = your engine is toast

gus5891

also i have a parts car with an engine in it how can i check to know if its any good everybody that i talk to said they had the engine firing but no reports of it ever runnin. also do yall know anybody in this area that works on rx7s other than the dealer. i'm in kenner, louisiana.....i also have a haynes repair manuel on how to remove an replace the engine an i am very mecanically inclined

gus5891

it Leveled off an was runnin good but now when i start it its smokin an it looks like steam. also the motor always ran at half on the temp gauge

gus5891

the parts car engine is ready to be removed i just gotta get my car apart an i'll be ready

gus5891

Help the wires are not matching up im screwed

Richter12x2

iTrader: (1)

Gonna probably need more information than that before anyone can help you. Do you have pictures of the wires that don't match? Or at least a description of what they go to?

gus5891

well i put the parts motor in. it made half a turn an locked up so i'm back to my original motor. My new question is= what does BARRS STOP LEAK do to a rotary engine. when my motor was out i spun the flywheel an got water out the exaust will barrs fix this or make it worse