DropTopRocket

To start off, I have spent the last month reading other posts and have found a ton of good stuff but I need some help connecting some related issues that dont measure up.

I was losing coolant which started as the leak on the heater hose below the oil filter. Fixed that but still losing coolant. Can't seem to find any other leaks so I assume that it is blown seals... but, shouldn't I be overheating constantly? I can idle for over an hour at 1/4 to 1/3 on the temp gauge no problem. Under load she tends to stay closer to the the 1/3 to 3/8ths mark??? In stop and go rush hour traffic she stays at the 1/3 to 3/8 1/2 is the the highest with the a/c running in said traffic which to me doesn't make any sense to me. I did replace the stat with a mazda OEM stat and a OEM stat neck rad cap where is when my problems started (hose blew etc.) I don't see any bubbles in the radiator and did the cap off rev test with no gushing water so needless to say I am baffled.

I was about to do the Yaw fix but don't know if it is really my seals or not. Doesn't smell anymore sense I fixed the heater core supply hose but if you do the 6k for 30 second test I get smoke now where I didnt' before. Can't see blue but it is acrid not sweet???? I know a rebuild is coming but need to get her through to January as I am saving for it now. Should I do the Yaw fix and see what happens or will that F'up my car? ICEMARK where be thou?

Amur_

That assumption's a helluva leap there, guy.

First off, how much coolant are you losing during what time period?


Overheating, yes. Geysering coolant out of the filler neck at start-up, yes. Funky-smelling smoke out of the exhaust, yes.




Those sound like normal coolant temps to me, guy. I seriously doubt that your seals are pooched.




So start thinking about other possibilities. Where are all the locations that coolant travels to?


I believe that doing the Yaw fix on your motor would be a tremendous waste of time, effort and money - everything you've described here says that you don't need that fix.

I'd suggest that your leak is at the heater core, inside the cabin. Coolant leaks from the unit, down and under the carpet where it is soaked up by the foam beneath the carpet.
Yank up the carpet on both sides. Look up front at the base of the firewall. See any green puddles? Is the foam moist/damp to the touch? Sniff all around in there. Smell coolant?

Dollars to donuts your motor's A-OK. Look elsewhere for the leak.

DropTopRocket

First it was from the FULL mark to the low mark, for which I then topped it off twice in one day where it has seemed to stablize but after a week of driving I see it is down about a 1/2 inch so I assume the system had a bubble which it burped and drew in more coolant. Also upon inspecting some more I now see moisture under the rad drain plug. My plug seems fine thou and upon visual after shutting down isn't seeping that I can tell but I still have some coolant on the plastic pan under the motor? I have also noticed that the temp rises under load (to 1/2) then goes down to 1/3 to 1/4 when sitting...

QUOTE]Overheating, yes. Geysering coolant out of the filler neck at start-up, yes. Funky-smelling smoke out of the exhaust, yes.[/QUOTE]

No Geysering and the filler neck is full when cold with no funky smoke out of the exhaust

I will pull the carpet today and check for coolant... although I don't have the infamous coolant smell in the car but do smell it from time to time in the engine bay??? I will check the carpet and foam and I am going to steam clean the motor and see if I can locate any other leaks in the system.

I thought that the normal OP Temp on the 88 N/A was at 1/4 to 1/3 max? That is why the 1/2 reading bothers me... It never ran that high until I replace the filler neck rad cap. Which also inspired me to change the thermo. I mean I could just be freaking out because a.) she is my only trans and b.) she is muhbubie

At this point I agree with you but am still concerned about the temp issue. Will update thread with details as the saga continues

scathcart

Coolant leak to the cabin is especially common after a hose change. Are you sure you tightened that hose clamp tight enough? Did you cut the old hose off, or twist it off with pliars?

If the clamp is not tight enough, or if the firewall nipple is not perfectly round, then you will leak coolant into the car. You should find it on the passenger side floor pan.

I know, I just sorted these identical problems out for someone else. It will only leak under pressure, and it can cause you to overheat, since the coolant system needs to be able to maintain pressure to cool properly.

Take the hose that you just replaced off at the firewall and make sure you have not crimped the nipple to a funny shape.

Amur_

Hint - for the hoses going to and from the firewall, use TWO hose clamps on each connection. It does make a difference.

Coolant on the undertray? That tells me that there must be a leak under the hood (although you may also have a leak inside the cabin, as I suggested.)


The thing about the coolant gauges is that you can never really rely on them for any kind of accuracy. After all, what do you have? An L and an H, with a big gap between them. That really pissed me off b/c it didn't take much on-line research to learn how important coolant temps are to a 7 owner.

So I put in an aftermarket gauge.

https://www.rx7club.com/showthread.p...hreadid=137825

Scroll 3/4 of the way down for some shitty pics.

One thing this gauge told me is just how useless the stock gauge is.

1/4 on the temp gauge is about 150-170F. That's a helluva range.

1/2 is around 190F.

There's a "variance" of about plus or minus 10F in what the stock gauge reports. My aftermarket gauge can be anywhere from 150F to 175F or so and the stock gauge will hardly move. And where the aftermarket gauge reports temp changes quickly (as can been seen when the e-fan kicks in,) the stock gauge is downright glacial.

And finally, what's showing on my stock gauge may not be the same as what's showing on yours. 1/2 may be 190F on my 7, but 1/2 may be hotter or colder on yours...

Normal operating temp for the motor is 180F. If you hit 240F, you risk blowing a seal.

Aftermarket temp gauges are not too expensive, and neither are gauge pods. Add it to your project list.

DropTopRocket

Running at the 1/2 mark on the stock temp gauge makes sense then (seeing I have the stock 190 themo from mazda).

Checked all the hoses again with no coolant in the car but still losing coolant. But I have found a current culprit. The drain plug on the bottom of the radiator is broken off and leaking slowly i.e. when under pressure!!! How totally gay is that?





Does anyone know what size the drain plug is and the tread pitch...?? It is a plastic part and I would like to replace it with an aluminum version...

Wankel7

On my TII I could not find the proper......drain ****. I got a mazda part for it.

James