blazerman

ok, i just got a 1990 rx7 vert. picked it up last thursday for 750.00. cars got 147,000 seemed to be in fairly good condition. ive been wanting a rx7 for a while now and when i came accross this deal i couldnt let it pass me by.

so, picked the car up last thursday night, took it home and parked it. got to checking it out and we noticed a small leak on the radiator right around where the factory part # plate is. so friday i got some parts from work, oil, filters, other maintence stuff. got home changed the oil out even though the guy said he had just changed it. then took it out for the evening. everything was going good. only problem i had was the add coolant buzzer/light had come on a few times. ranging from 1-2 seconds up to 20 seconds or so. well when we got home as soon as i pulled in the driveway a cloud of steam came from under the hood. opened it up and the radiator had cracked the whole way accross on the top.

so i got up the next morning and called work to get a new radiator. got it put in that afternoon. here is a link to the first thread i made. so ill post it to shorten the story.
https://www.rx7club.com/new-member-rx-7-technical-256/need-cooling-system-help-upper-rad-hose-collapsing-852717/



so, everything seemed fine after we got all the air bubbles out of it finally. well the past few days the add coolant light/buzzer has been coming on. but it hasnt done it in the morning on my 13 mile drive to work. but when i get off to leave for home in less then 2 miles the thing starts coming on. like before it migth come on for a split second or 20 seconds.

the overflow bottle has coolant in it, the main coolant level seems to be full, only leak that i found was the heater hose under the oil filter so i replaced the clamp on it and it seems like it fixed it. it was never a big leak, the only way i found it was after i shut the car off and you could hear it hissing.

there is no ther leaks that i have found, coolant doesnt seem to be getting burned in the combustion chambers. no smike from exhaust and we havent seen the little tell tell bubbles in the coolant. cant see any where on the sensor wire that could be grounding out. new thermostat and upper hose. temp. gauge hasnt gotten over right under half since we got the main issues fixed.

ive searched the forum and read thru other threads of people that have had the same issue or a similar one and havent found a fix or they have never posted any updates to there problems.

so i really need some help on this. if this thing had a regualr motor id probally have it fixed by now. but these rotaries are a new thing to me.

so if anyone has some ideas they would be much appreciated.

thanks

ATRON3000

What brand t-stat?

jjcobm

iTrader: (18)

Try to remove bubbles from the system by jacking the front of the car up in the air. Run the car without the radiator cap for about 30minutes with heaters on full blast. You still have air bubbles in the system and this will remove them for sure.

It would be a good time to replace the thermostat with something new by the way....

ATRON3000

he did replace t-stat, but with what brand is important

pfsantos

iTrader: (1)

Did you overheat it (gauge past half)? Does the coolant level at the reservoir keep rising, but you have to keep adding coolant to the rad/engine?

blazerman

oe
have done that. when we replaced the thermostat we had it on ramps and let it run for almost an hour with a lesle funnel.(i just call it a burp funnel).
oe
the day i put the radiator in it did start overheating while i was taking it to my buddies house so they could see it when it was making the noise and collapsing the upper hose that i mentioned in the thread i posted. it was filling the overflow then and overflowing it.

but since we put a new thermostat and upper hose and i replaced the hose from the radiator neck to the tank it is always at half.

during my lunch break i check the coolant and it wasnt really that low.took maybe half a cup of water to fill to the top of the neck. i also pumped the upper hose about 50 times just to make sure there was no air since i havent let it really burp since i replaced the clamp on the one heater hose.

if it was entering the combustion chamber from what ive read it should be fairly noticeable. theres been no smoking and the car runs cooler then it did before i replaced the thermostat. and with the funnel on i havent seen any of the small bubbles like people describe.

Hypertek

iTrader: (3)

check for water leaks? around water pump, behind water pump housing, lower radiator hose area, throttle body heater hose, water hose under alternator etc. when i first got my rx7 and changed the water fluid, i thought i had got all teh air bubbles out then it started givin me the buzzer for a while til i eventually learned how to properly bleed it.. just took some time to figure it out.

nycgps

iTrader: (4)

did you align the thermostat correctly?

pfsantos

iTrader: (1)

What he's talking about is this:

https://www.rx7club.com/showthread.p...ing+thermostat

See pictures.

Also, make sure your heater is on "hot" so you don't get air bubbles there.

blazerman

havent found ant leaks. the only place i gound was the heater hose under the oil filter. took the old crappy clamp off and put a new one on it.
yep. the little flapper or whatever you call it is in the 12 o'clock position if your standing facing the side of the motor on the passenger side.


also when i was at lunch i drove it up the street real quick. probally about 4 blocks and the buzzer came on for about 10 seconds.

funkjaw

iTrader: (3)

You probably still have a leak somewhere. I have dealt with the dreaded buzzer quite a few times in a couple of my Rx7s. The other thing is the buzzer also comes on for low oil so check to see if you are burning/leaking oil or are low.

blazerman

oil has been good since i changed it last thursday

blazerman

nice write up.

but mine is different from that one. your thermostat is bigger then mine. it has a o-ring that seals it. no gasket. and i dont have the good water neck with the cap. only cap mine has is the radiator one.

KKMpunkrock2011

iTrader: (5)

I know on both my last and my current rx7 the coolant reservoir has a nasty leak somewhere. the one on the last one was easy to find, this one not so much.

daviddeep

iTrader: (4)

That's because you have an S5 (89-91). They have the plastic neck at the upper radiator hose with no filler cap. It is sealed with an O-ring rather than a gasket.

blazerman

there are no visible leaks

blazerman

also i have another question but didnt want to start another thread for it.

i noticed that the fuel lines hoses that connect to the hard lines right there near the oil filter have something i find weird connected to them. you have the line that comes from the filter then i guess its the return line that runs right beside it. well theres is a weird union deal on there. the lines stop and go into a union then out of the union and back into rubber hose till they get to the hardline at the motor. but what i find strange is the union deal. the easiest way to describe it is it looks like a H meaning the 2 hoses are connected.

is that a normal thing on these cars or is this some weird crap someone put on and didnt know what they were doing?


edit: I also wanted to thank everyone for there help so far. hopefully ill get it figured out. hopefully it doesnt need a rebuild yet.

daviddeep

iTrader: (4)

I believe Mazdatrix used to sell an H-type fitting that you could mount on the fuel lines right by the oil filter as a band-aid for leaky fuel injectors to prevent flooding. Not sure how or if it actually worked, but that may be what you're describing. A photo would help.

pfsantos

iTrader: (1)

The mazdatrix "h" is a band-aid solution to relieve fuel pressure. The middle of the "h" has a tiny hole. When you shut the car off, pressure is relieved from the supply side to the relief side. It doesn't affect fuel pressure because it's so small, but helps relieve pressure after the car is shut off. Instead of fuel pressure passing and being relieved through leaky injectors, it goes through the 'H'. It's essentially a fix for cars that flood due to leaky injectors.

pfsantos

iTrader: (1)

Just remembered...about your coolant loss/leak/whatever.

Two things... (1) Sometimes the hose to the coolant reservoir leaks or leaks at the ends and you loose coolant there.
(2) Sometimes the negative pressure side of the rad cap fails and the system will let coolant out (to coolant tank) but won't suck in coolant back into the system when the car cools down. I'd throw in a Mazda rad cap if you're not sure about its condition.

Evil Aviator

In addition to the split end, it is common for that upper heater hose to get a pinhole leak that is nearly impossible to detect because it only leaks when you are driving the car and it stops as soon as you stop the car and open the hood to take a look. The hose damage is usually caused because the two o-rings under the oil filter pedestal crack, which leaks oil on the hose, causing leaks and cracks. If you still have an unknown leak, I recommend buying a new hose and two o-rings and see if that helps. In fact, you may want to replace them anyway, as the current hose is probably already fatigued to the point that it could fail at any time, and replacing the o-rings now ensures they will be good for another 50,000 miles or so. Once replaced, take care not to drip oil on the new hose when changing the oil/filter.
2 each: http://www.mazdatrix.com/getprice.as...m=10-1601-9954
1 each: http://www.mazdatrix.com/getprice.as...m=61-2110-FB03

http://www.mazdatrix.com/c-bleed.htm

misterstyx69

iTrader: (142)

see if you can find a place that does 'loan a tool"..
you should Pressure test the cooling system.
If the rad went "Kablewy" and you found a bad hose,then My Thinking is,the rest of the system isn't far behind in letting go.I'd Pressure test the Cooling sytem to fibd if you have any places that are either letting Coolant Leak out or letting air IN.

RRTEC

iTrader: (13)

I would say that if you are pulling out your hair over this issue, this car may not be the right choice for you... Be prepared for many more headaches.

SecondGenPat

I found that on mine a month ago, similar symptoms to what blazerman is describing. I found that after I parked the car for a night and came out in the morning I would be greeted with the buzzer, my overflow tank was slowly filling up when the car was heated but not emptying when the car cooled.

!!S4 car!!
The best way I've found to bleed the system is to warm the car up (t-stat open):
.Make sure the cooling system is full (engine off)
.Set logicon to max heat
.Start engine, let it reach operating temp (t-stat open)
.Park the passenger (right) side tires on a curb or parkstop
.I then slowly open the bleeder plug, but never remove it, until I see a constant flow of coolant running out
.Then tighten the bleed plug
.Move the car to level ground
.Fill the cooling system if necessary (engine off)
.Repeat if necessary

That should do it. If you drive for a day or two and the buzzer comes back you either have a slow leak, faulty pressure cap, or missed some of the air in the system.
Hope that helped
-Pat

blazerman

ok, this must be one of those then. i pulled it off tonight, just because both of my buddies that have built rx7 drift cars had no idea what it was. after looking at it and messing around i finally came to the idea that it must have something to do with the good ole flooding issue. im going to see how it cranks in the mornign and if it is a pain ill put it back in.

well, when i left work the buzzer came on of course. but this time it stayed on for almost 2 minutes so i pulled over. well, that heater hose under the oil filter let loose. once i pulled it off the end was all swollen and you can see where it failed. so i cut the bad section off, hooked it up then filles it up with water. once i got home i put the lesle funnel on and let it get all the air out.

it was fine running for about 30 minutes. just took it out a little bit ago and was fine for the drive to where i was going. but as soon as we left the buzzer came on. we were parked on a pretty good inclined driveway so it might have helped more air get out.
going to go try to get one tomorrow. really wish i wouldnt have sold my good one when i stopped working in garages.
honestly, if you could see what i go thru with the blazer ive been building this is nothing. the only part that is driving me nuts is im very good with regular engines but this is my first dealings with a rotary.
ill try that tomorrow. but i dont have a bleeder valve. been trying to get one local but no luck.



my buddy came over tonight and even he is stumped. he says that its not getting burned up in the engine because of the way it is running and there being no smoke or bubbles in the coolant. so i ave no idea. it must have a bunch of air in the system. but i plan on working on it a good deal tomorrow and hopefullwe will get it worked out.



once again thanks for all the help guys.


ps, ill post pics of the h fitting deal tomorrow.