The Problem Game!
 

Ok, I need some more opinions on this, as the results of dicking with the car today are supporting a theory I don't want to accept without someone agreeing with me.

So to start things off:
Radiator cap is not an issue.
Tstat is not an issue.

Pressure is present in the cooling system. I've tried bleeding the system, and at times I was convinced all the air was out. But, with the cap off and the system bled the pressure (amount of coolant overflowing from the cap) is directly related to RPM. the system is somewhat stable at idle, with few bubbles, and eventually the radiator can be filled and the bubbles pretty much go away. Then, with the cap still off, as the RPM increases so does the amount of coolant bubbling over the top. Engine is at running temp the whole time, and the coolant coming out is cool to the touch. After letting the car go back down to idling RPM the flow continues for a while, then stops. Once it stops the fluid level is lower (obviously) and now steam can be seen coming out of the filler neck of the radiator. Heater was on full blast the entire time.

Lets try to keep it on topic and avoid the radiator cap and tstat suggestions.

Alright guys, what do you think the problem is? If you need more info just ask.

Your water pump works.

*ends smart remarks*

I do not get it. If fluid is coming out of the radiator cap with the cap on, then obviously the cap is bad.

EDIT: Or the sealing around the cap. Is the radiator tube dented or cut anywhere around the area?

Sounds like a bad coolant seal. Pressure from combustion chamber is pressurizing the coolant system causing the coolant to bubble/overflow. Only fix is rebuild.

Cap was off the entire time.

Put the cap back on and the coolant should stop running out.


I am terribly confused with this thread. :confused:

I was thinking that, but compression does not cease when the car reaches idle speed, which is when the coolant stops overflowing. Maybe it could be?

Coolant should not be pouring out of the radiator neck while the engine runs, with or without the cap. Also, with the cap on it just pressurizes the system to > 16lbs and it goes to my overflow and makes a bigger mess.

I was assuming that you already had the car running which is why I was like "hey there... um.. put the cap back on".

The cap I have on my rad is 9lbs IIRC.

This is the conclusion I came to as well. I'm fishing for second opinions and possible alternate problems I can eliminate before giving up on this car. Sadly I was dumb enough to buy an rx7 and pray not to have to rebuild it for a while. Lucky me, it came with this problem.

Stu: Here is his other thread for more info.
https://www.rx7club.com/1st-generation-specific-1979-1985-18/more-cooling-system-woes-735943/

Although the gases from a blown water seal is always there (engine running), more gases are generated with higher RPM. A blown water seal can show no overheating on the gauge, but still show bubbling/overflowing of coolant with or without rad cap present. The combustion chamber is 100s of psi, so it doesn';t take much to pressurize the coolant system to 16lb+ to cause overflowing through the cap.

Sorry, man. Sounds like it is time for a rebuild or another engine.

Yeah that was my thread too...I wanted a second second opinion as the fact that this car is done for is a hard one to swallow.

Yea I have missed that last turn before. One time driving 200 miles and the coolant lvl light came on. Pulled over and juice was all over the place leaking out the cap. Last 1/4 inch turn not done.

Ah, thanks! Learn something new today.

DUDE. You had another thread on this and it came to the same concllusion as this one. Your coolant seal/jackety thing is bunk. = rebuild and salvage what you can before you toast the engine

I can understand you not wanting to believe this, i can. But some of the more respected members of this forum have already told you this is the case so come on. You are asking opinions. So instead of taking the opinions of 50 people who only kinda know what they are talking about. Take the opinion of 2 or 3 who have EXTENSIVE knowledge of rotary engines

I think you have a seriously blown internal water seal. I've never had one that bad, so I don't know if the Temporary Internal water Seal Fix will work or not. But it might be worth trying. With such a severe leak we might be able to answer some questions about the best way to cure the colloidally suspended copper mixture. It'll only cost about 10 bucks and a days work to do it, so I'd give it a try. You never need to exceed idle RPM to do it so the disrupting pressure can be controlled.

Do you know anything about the history of this car?

Another possibility might be a partial clog in the radiator, restricting flow back into the motor.

But everyone else is probably correct. Sorry... :(

i was also going too say coolent seal
but everyone beat me lol

one of the tests i do when buying a rx7 is watch the radiator for bubles and water raising to indicate if the water seals are ok

sorry man maybe try what biffle is offering ..

to be honest good rebuild is in order if your not rich and you have good compression numbers a gasket and seals kit would be the easeyest way..

My previous thread didn't have the updated information from my work today.

As far as opinions go, I can tell who knows what they're talking about and who doesn't. I'm not going to "check my hydrospanner" or some equally moronic thing because someone like you tells me to.

If you don't have anything to contribute to a thread you need to simply not reply.

This car's going up for sale, I see no reason to try to rely on such a volatile system as the Wankel engine. It was a lack of foresight on my part to buy something cool rather than practical. Neat car, but I'm not that much of a masochist.

[Flaming begins here.]

Im not going to flame, and i apologize, you caught me at a bad time hence my reply.
Good luck with the sale of your car

I should of quoted the other guy. Was not trying to say this particular prb was a rad cap.

What kind of condition is the car in otherwise?

Body's in pretty good condition, a few dings and scratches that have been covered with touch up paint, and a crappy paint job. The interior is OK at best, it's not trashed just showing it's age. Everything else aside from the stereo works. Transmission shifts smoothly, and wines a bit but I haven't changed the fluid since I bought it...I've been dealing with other issues (such as this blown gasket) and haven't been driving it so it wasn't high up on my priority list.

Why? Need an 85 GSL-SE?