hey i have an 87 GXL that is having overheating problems. first of all it seems to do fine and stay at a good temp for a while then all the sudden the temp will start going up real fast and coolent starts coming out of the radiator overflow bottle. Also it doesnt seem to have any pressure because ill run it and let it sit for about 10 min and take the cap off and no pressure comes out at all. but this all seemed to start happening after i unclogged the line that goes from the radiator to the radiator over flow bottle, there was a little metal pice connecting the two lines between the bottle and radiator that was curroded and wouldnt let coolent be sucked through it. does anyone have any idea what is going on?
thanks
Ryan

 

oh yea and 1 other thing most of what was in my radiator was water because i had the heater hose brake on me and had to keep filling it with water on my way home and never drained it and filled it with the proper amt. of radiator fluid/water

 

DO you have your underbody covers and fan shroud?

 

From our esteemed Moderator, Mr Aaron Cake.

http://www.aaroncake.net/rx-7/cooling.htm

 

You need to have radiator "fluid" because it has a higher boiling point. That could very well be why the car is overheating.

Secondly, replace your radiator cap.

Third, close the cap back up, start the car, and squeeze the upper rad hose when the car is hot. it should be hard to squeeze. If you're able to squeeze it and it stays folded, or is soft to press, your water pump is failing.

Failing that, determine whether your car overheats when moving or when staying still, or at high rpms, or what.

-Ross

 

put your fan shroud on.

how long has this metal thingy been in the line?

 

damn i just wrot so much and it didnt post so here it goes again
I have the shroud and underbody panels on, I think it may be the cap im buying one tomorrow along with a thermostat from the mazda dealership, i havent tryed squeezing the hose yet but ill do it tomorrow. it seems to overheat while driving because i ran a radiator flush through my car sitting still for 20 min and it never got above 1/4 on the temp guage and when i drained it and filled it with water and ran it another 15 min it stayed at about 1/4. i havent put the coolent/water mixture in yet because i ran out of daylight so i am just letting the water drain overnight and ill finish tomorrow

 

anyone have any other ideas on what it may be

 

i thought you were getting a cap and thermostat? have you done this yet?

 

flush ur system radiator/engine and replace with 50/50 mix, i kinda had the same problem a week ago but i flushed now stays cool!!

 

i would actually say DONT use an exact 50/50 mix.. (unless anyone can say otherwise) rx7blazin is in the south where he doesnt see winter. the anti-freeze that will be in the water to make the coolant is strictly for lubrication and prevention of corrosion. he doesnt need too much a/f because the car will not see below 0 degrees celcius temperatures.. that and water cools better than straight a/f..

 

i heard 70/30 thats what im gonna use cuz 50/50 protects way below 0 and to like 70-80. nope havent got the cap and thremo yet ill get back with you after i do all this see if its still happening

 

well i wnet to the mada dealership and there parts dept. is closed so ill have to wait for another day to do that. BUt i have one more question you know the stem that comes off the top of the radiator that has the hose that runs to the radiator coolent over flow bottle, it also has one single wire coming off of it?? well does that have a valve in it of some sort to control when to let coolent in/out? asking this becasue that is my main concern is that that valve is faulty and is not allowing the pressure to build and instead the pressure is going out into the radiator overflow bottle. i think this because when i take the cap off even after running it it has little to no pressure as im taking the cap off but it has plenty of pressure coming out the radiator overflow bottle cuz it will start poring over the top.

 

I could be mistaken, but I thought plain water had a higher boiling temp.

Anyhow, when you added coolant after the hose broke, did you properly get all the air out of the system?

 

nope but that was a while ago

 

when you replace the stat, make sure you unscrew the bleed valve when you refill it and "burp" it to make sure you get the air out. then drive it for 20 mins and repeat.

 

thats what i did after i ran the radiator flush and filled it with radiator fluid/water

 

i used to live in Abilene and i used 70/30 with a bottle of water wetter. Never had a problem with it that way. Worst case scenario, if none of this works, you may need to rod out the radiator.

 

yep it does. but if you run straight water the jackets inside will corrode, and thats a big mess which youll be paying out the *** for later.

a/f is to prevent corrosion and keep things 'lubed'.

 

well if all this doesnnt work i found somone with a s5 radiator i can buy and put on there and if all that doesnt work then ill say ****

 

well the bolt to the thermostat broke, thats just great i knew that was gonna happen and there was nothing i cold do to avoid it, guess thats why your supposed to change your thermostat every year huh so you bolds dont get stuck in your block

 

Unscrew the other bolt pull the thermostat housing off and use some pliers to unscrew the broken bolt. You should be able to get hold of the broken bolt from underneath as well. Sounds like a thermostat problem if you dont fix it soon it will kill your engine. Also tighten all hoses.

 

i need a pare of vice grips i have some but there broke im not going to get regualar plyers and take a chance of screwing it up cuz then i would have to replace the whole housing, i already go the old thrermostat out but cant do anything untill i get that bolt out

 

ok well lucky i got the bolt out wihout damaging anything or beaking it off furth but now im gonna have to wait till mon to finishis this all up cuz i cant find a place opend today or sun that have the bolts. and the mazda dealership doesnt have the right type of coolent lever sensor that i have and cant find one so i dont know what im gonna do there

 

you can order it from mazdatrix. you should be able to get the bolts from NAPA.