david_j1973

Hi Folks,
i finally got my car running properly but i have a problem.
its an 86 n/a.

my car runs fine until it reaches about 1/4 on the temperature gauge then it starts pumping hot water out the overflow bottle overflow hose.

i have the overflow bottle filled to the correct level.

there are no air bubbles in the coolant while the engine is running so i dont think there is compression leaking into the water jackets.

also when the engine is idleing and the radiator/filler cap is off water slowly keeps coming out of the filler and when you rev it the level goes down and when you back off the throttle to idle the level comes back up and starts coming out of the filler.

it does the same thing with or without the thermostat in, the only difference is the engine warms up a little faster with the thermostat in like it should.

i think it may be a blown water o ring in the engine because i did a check under the oil cap and there are water drops on it and in the top of the oil filler tube so im thinking the outer o ring of the rotor housing is leaking moisture into the oil environment.

the oil doesnt have any water in it, its not milky but there are water drops under the oil cap and in the top of the oil filler tube.

other than that it the car goes very well for a 6 port, i think the large exhaust and aftermarket ecu work well together, maybe there is a bit of a street port job in it, i dont know as i dont really have any history on the car.

i only revved it to 4000 rpm while test driving it but im pretty impressed how well it goes.

any help would be greatly appreciated.
Thanks.

Leonel95

First check to see if the tail pipes are smoking a bit...for sweet smell

How is the idle?


Take out the plugs and check for any signs of water/cooling on them.

And about the bit of water on the oil cap it tends to happen.

lastphaseofthis

iTrader: (8)

sounds like it's minor blown to me.. drive it , checking coolant level often, until it becomes major

david_j1973

Hi Leonel95,
it idles fine when warmed up, no smoke either.
i will check the plugs too.
so it does happen, water drops on the oil cap ?

Hi lastphaseofthis,
can only drive it or run it until it hits about a 1/4 on the temp gauge then it just keeps pumping water out the overflow pipe on the overflow tank.

i thought maybe there is a blockage somewhere in the cooling system, is it safe to use radiator cleaner on rotaries ?
does it damage the water o rings at all ?
i have that loctite radiator cleaner crystals that you put in the radiator then run the engine to temperature, then drain the cooling system and refill with new coolant, i was going to try it but was worried that it may damage the o rings in the rotor housings.

Thanks for the responses,
Much Appreciated.

SpikeDerailed

iTrader: (7)

Check the thermostat and radiator cap, most caps dont seem hold the pressure as well as they should.

Molotovman

iTrader: (49)

Check the cap, last resort you could have the system pressure tested. Try to find a 16psi cap locally, even though it's supposed to be 16, it'll open up earlier. The same can be said for a 13psi cap, that's why you Want to get the higher pressure one.

RotaryEvolution

iTrader: (30)

people actually read my posts?!

lol


anyways, yes, replace the cap with a higher psi aftermarket one or an OEM 13psi cap and try it again, if the same result occurs then you probably have compression pushing into the cooling system. coolant doesn't necessarily have to push into the engine for the coolant seals to be faulty if the broken seal is minor.

assuming the engine is original it is at the end of its lifespan so save your nickels.

Leonel95

i know this might sound out of place...

what kind of coolant are you using ?

50/50 blend?

perhaps by now there's might be a higher percentage of water compared to coolant.

hence there's more pressure?

david_j1973

Hi Folks,
Thanks for all the responses.
i put a new thermostat in it, it does it with or without a thermostat,just the engine warms up quicker with a thermostat in it.
i am using the radiator cap that was on the car but i did buy a new one when i bought the thermostat but for some reason didnt put it on yet, i will try it.
i got it at an auto parts shop i go to and the guy looked in the book for both the thermostat and the cap to suit the car but they are aftermarket and not original mazda.

regarding the coolant, its just plain water, i did put 1 liter of pure coolant/anti freeze in it and the rest water when i put the thermostat in it but i didnt like the look of all the rusty water so i took the bottom rad hose off at the engine and got the garden hose and back flushed the radiator to try and clear out the core because there was an awful lot of rust in the thermostat housing and i thought maybe the core might be blocked.

i then put it together without the thermostat and just put plain water in it because i would be putting the thermostat back in later, i just wanted to see if the water was circulating through the cooling system and was feeling the core to make sure it was warming up evenly.

i then got the car up to operating temp (1/4) on the gauge and it started pumping water out the overflow bottle.

i put the thermostat back in and it does the same.

i will put the other liter of coolant in it and the new cap and see how it goes.

regarding rebuilding the engine, i think it has been done at some point in time as someone has done some work to it,steel flywheel,turbo box,aftermarket ecu and exhaust but who knows.

i have already put about $3000 into the car and was quoted another $4000 by a rotary shop to put a full seal kit through it but the car isnt worth that much more cash, with auto electric work still to be done and registration im looking at around a total of $9000 minimum and i can buy an fc here at anytime for around $7000 with big turbo engine,ecu,exhaust,adjustable suspension,big wheels etc on the road registered etc so its not worth spending anymore money on it if the engine needs a rebuild, i will just cut my losses and sell it as an unfinished project and let the new buyer know what problems it has.

i am on a disability pension so finding another $4000 just isnt possible for now.

i would rebuild the motor myself as i have done a few 13bs back when i was younger (early 90's) but there is so much crap on these rx7's in the way of pollution control,wiring and all the rest i dont really know where it all goes and dont have the patience anymore (due to my age) to sort out any problems with connecting up all that crap.

i used to work on carbureted rotaries before (r100's,rx2 3 4's) and they are much simpler, you can actually see the engine !

but with the fuel injected rx7's and later there is so much crap on the engine there is so many things to connect up or go wrong and i just dont have the patience anymore.

one of the reasons i left the mechanical trade was because of fuel injected cars and all the crap that can go wrong with them.

i will try the new cap and see how it goes,if it still does it i will try and buy a 16 psi cap and see what happens.

Thanks again for all the replies and help,
Greatly Appreciated.

Logicalbomb

iTrader: (1)

4000 for rebuild is steep unless they're giving you a real beast in return. As far as smog emissions etc if your state doesn't check don't hook it back up lol. My engine bay looks 90% more clean than any stock I have seen. It's probably the cap unless you're mixing coolant with oil smoking like a big dog and running around town smelling like a sweet roll.

david_j1973

yeah $4000 is a bit rich in my opinion considering a full seal kit is about $1300-1400 trade price.

and that was $4000 plus anything that it may need, that was as long as all the housings,plates and rotors etc were all in spec and reusable.

i tried the new cap i have and it is only .9kg/cm2 and i still does the same thing.
i just purchased a toms high pressure cap, 1.3kg/cm2 but have to wait till it arrives from the u.s.

here is a vid of the car running with the overflow and the gauge to show where it starts overflowing, you will notice a beeping sound when in the car, i have no idea what that is,
it starts at various times,
http://www.youtube.com/watch?v=oanpJ...ature=youtu.be
the next vid is when its not running, you can hear the bubbling in the overflow tank,
http://www.youtube.com/watch?v=OZ3HH...ature=youtu.be

when switching the ignition off there is a big spurt of water from the overflow then it settles down to where it is in the vid.

i dont know if the gauge is faulty and showing the wrong reading and the car is just overheating or there is a major problem, blown o ring.

i removed the fan shroud so i could feel the radiator core to see if it was blocked so i dont know if it needs it so it can suck air through the radiator and therefore cool the radiator.

any advice would be greatly appreciated,
Thanks.

Logicalbomb

iTrader: (1)

That beeping is the warning sound for low coolant since that is the #1 killer of rotaries. You can find full rebuilt engines for less than 4k and normally they're even Turbo engine (although you'll need all the turbo parts to make her fly). Also the 2nd video lets us know that it is boiling. I know that until you find the solution anti-freeze may seem expensive but a 50/50 has a higher boil temp than straight water. I would also suggest throwing a little wetter than water in there to help cool things down. I wonder why it is heating so quickly? I know my car had the same problem and I did what many people on this forum will FLAME ME FOR!!! (you know who you are haters) but I actually ended up checking through all the hoses, blocking off the ones that I didn't need, and removing the thermostat completely while using a high pressure cap. It kept my system free flowing and allowed for better cooling during hot weather. I know many people are timid when it comes to doing this and claim to have doctorates in why I am wrong, but it works for me.

Also, make sure that you're filling this correctly when you do it because air pockets will make that do the same thing! Yes they really exist! So what I did was filled at radiator with the fill neck cap near engine open until it was at the top of radiator. Then I put the cap on the radiator and unscrewed that little pressure release valve located on the left corner of your radiator. I filled up from the neck of the coolant intake by engine (above thermostat) and waited until it started bleeding out of valve and reached near the top of the fill neck. Tighten the bleed valve before capping it down and you should be fine.

IF none of that works for you make sure you check your oil to see if there is coolant in there. I swear you'll know when you're burning radiator fluid because it makes your car smell like sweet rolls only super nasty. Anyways, good luck and let me know how it goes! Those videos where extremely helpful as well.

lastphaseofthis

iTrader: (8)

great minds.

esjoson1126

Same exact symptoms I've got, stop tinkering and confusing yourself time to rebuild your engine. I wasted a lot of time and effort analyzing what the problem was, which we all knew already (blown coolant seals), but hey we're trying to get by, maintaining a rotary is not cheap. I rebuilt my engine and it's back on the road good as new. Good luck.

david_j1973

Logicalbomb, Thanks i will try and bleed the cooling system and see if that helps, i will also buy some more coolant but i have to wait til the cap comes from the u.s. (im in sydney)to get it all done.

regarding rebuilt engines, i cant find one here, basically you have to take your car to a rotary shop and have them rebuild yours, if i could get an exchange rebuilt engine that would be great and much cheaper, i will make some calls around to the various rotary shops and ask if they can do an exchange rebuilt engine but i wont hold my breath.

the only problem then is putting it in and connecting up all that crap correctly.
thats the thing stopping me from doing the job myself, the rebuilding the engine part is no problem as i have done many early 13b's, its very easy to do, its all that crap on the engine in the form of hoses,fuel injection crap etc that i basically have no patience to sort out and diagnose problems if i get something wrong.

esjosen1126,Thanks for the info, i will try a new cap and coolant etc and see if that helps and if not i will cut my losses and sell it to someone who can afford to rebuild the engine, i will let them know about the problem and get what i can for it.

i guess this will sound like a bit of a rant but to anyone interested, its pretty well known here that the $4000 the rotary shops here quote you is really a starting price, then when they pull the engine down all of a sudden you need new rotors, or very expensive second hand ones,same goes for rotor housings,endplates etc and once they have removed the engine and pulled your engine down and tell you the price they have you by the *****,and if you cant afford it you get your car back in pieces and still have to pay them a huge price for the work they did do.

and like i said, im on a disabilty pension, i cant afford $7-8000 for a standard engine.

the majority of people that go to rotary shops here in sydney for work to be done have a disposable income and have no problems dumping $10000-20000 on a car at a time, i cant.

i would be very happy just to have a standard running rx7, i got this car cheap and have already dumped $3000 into it, and it was on budget to be on the road for a total of $5000,which is alot of money for me, thats basically more than its worth but it was acceptable to me, now if the engine needs a rebuild its way over budget and to dump thousands more on it is just stupid.

like i said, i can buy one here with all the work done that someone else has spent $20000 on any day for $7000 on the road so spending more cash on this one would be stupid.

the reason the cars are not worth what you spend on them is because rotary shops here are way over priced, they know they supply a service that most mechanics are afraid to provide (through most mechanics own ignorance), so they have this cartel mentality where they get together and charge basically the same huge prices for the same service and you have no choice except which one you want raping you.

back when i was an apprentice in the early 90's rotary shops charged $500 to remove and replace the engine, $500 labor to rebuild the engine plus parts, thats where they made their money, getting the seal kits trade price from mazda and charging you retail and if you needed rotors,housings etc they did their best to help you keep it within your budget with reasonably priced 2nd hand items.

and we all know that it takes a couple of days to do the job, unlike a piston engine that has so many moving parts and clearances etc that it takes weeks to get the job done.

but now its lets get as much money as we can out these suckers because we can, most mechanics, like most people are of questionable character.

i know this because i worked in the trade and rarely saw a mechanic do what is required and not extra unnecessary work to extract as much money as possible from the customer.

anyway, i will see how i go and update when i get the cap etc.
Thanks for the responses,
Much Appreciated.