MazdaRx7Power

ok so i let my bro use my car which i should have never done in the first place. so i go to the store in my car when he gets back and its idleing funny and has bad acceraleration. so when i come back out from the store my friend sees coolant on the floor so i was like wtf? the overflow tank was almost to the top and the screw that is at the end of the hose popped off. so i put a screw in to replace it and when i get home i hear the coolant blowing. but the temp gauge was always half way. never passed anyone have a clue why it boiled, was it cause it had air in the system cause of the screw comin out? i'm prayin it didnt damage my car or else my bro is payin for my ****.

hypntyz7

WHen its fully cool, remove the cap and fill it back up. IF you have an 86-8 then remove the bleed screw on the pass. side of the radiator while doing so, until coolant comes out of there, replace the screw, and continue filing until the cap is full. IF you have an 89+ then you dont need to worry about it, just fill normally at the cap.

Wait a few minutes with the cap off, and oberve to see if you can keep it full, or if coolant is going somewhere. Watch for small leaks, at the heater hoses, TB hoses, water pump and weep hole, etc. Lots of places for small leaks on an FC. Probably should check your fan and shroud, flush coolant, etc. too, to find out why it overheated in the winter idling.

BhamBill

It may not be boiling. It could be a blown seal pumping air into the system.

MazdaRx7Power

what seals are we talkin bout here?

GothicBlade

I'd say that would be the coolant seals......

MazdaRx7Power

where are they located? how can i change them? if i have to rebuild someone shoot me now!!!!!! how will i know if its the seals? wouldnt their be coolant in the oil if it was the seals?

No7Yet

No, there will be exhaust in the coolant.

Follow HYpntyazntanaza's :p advice, then check for exhaust in your coolant, then have your coolant system pressure-tested. If it fails all of these, it's rebuild time.

To be fair, tho, it's not your brother's fault. There's not much someone can do that will make the coolant seals go boom - if it were an apex, it'd be different, but it's not...

Brandon

GothicBlade

Allright, I'm by no means an expert.... but this is what I know.

The coolant seals are on the rotors, towards the center. They keep coolant and exhaust seperate. Or something like that. The reason your coolant is 'boiling' is because exhaust is blowing past these seals and into the coolant tract. I *guess* you could liken it to a cross between blown piston rings and a blown head gasket in a piston engine.

As far as I know, youre going to need a rebuild. Then again, like I said, I'm new to the rotary world.

Time to kill your brother.

No7Yet

Heh You're wrong, but you gotta learn sometime, right?

Well, actually, the coolant rings are on the outside of the combustion chambers, in between the rotor housings and end plates. Coolant only flows "around" the motor - not through the rotors. So the coolant o-rings are like the head gasket.

you're getting them mixed up with the oil control rings. The rotors are cooled by pumping oil through them - they get really hot, and, well, so do the rotors. That's why rotaries have oil coolers. They're like piston rings (in a sense).

Read my last post - IIRC, there's no real reason to kill his brother. It'd have died no matter who was driving it.

Brandon

GothicBlade

Right. Thanks for the correction. : )

As for killing the brother... you must have posted while I was typing my response... oops.

So... umm... dont kill your brother... just... wound him

hypntyz7

Someone really needs to make an FAQ listing or something for these things, maybe Ill make up my own pageone day.

TO test for bad water seals, do this:

Allow engine to cool, fill at cap until water level is as high as possible, where youd normally fill it. IF it mmaintains the level without air bubbles or draining down, its a good sign the system is well sealed. Leaks can also cause the water to keep draining. SO anyway get the water level as high as you can.

Disable fuel by pulling the fuse closest to the engine on the underhood fusebox. THis will keep the engine from starting up, making it easier to observe.

A friend is helpful, but you can do it yourself. You want to crank the car over with the water filled up and the cap OFF. You want to watch the area where the cap goes, to see if water remains stable(good) or shoots out like a guyser, as if under pressure(bad). The engine does vibrate a little on cranking, so take that into consideration if some water spills out, but it shouldnt be much. IF it shooots a guyser about 6" or more high, your water seals are shot. SOmetimes in the beginning it wont be very noticeable and consume only a little coolant every few days, but as you drive it, it gets worse and worse, eventually making a 30 minute trip impossible.

Most of the time, if you dont allow one to overheat the first time, the seals remain good. Yes, sometimes they just plain go bad for no reason, but sitting for months undriven hurts them badly, sitting with low or no water hurts them worse, and overheating only one time kills them for good. IF youre wondering what they are, picture a rubber band about 1mm thick, and about 1 foot in diameter, thats all that keeps the water and combustion seperate, adn over 10 years or more of run time they deteriorate, just like any other rubber seal.

MazdaRx7Power

if the seals were messed up wouldnt the car smoke?

MazdaRx7Power

ok i filled it to the top and drove for bout 10 mins. then came home, and didnt boil water still there! so can it be my plugs got somehow messed up. cause now the car doesnt acceralerate good?