Ok, the legal settlement I'm waiting for to use to have my car fixed is taking forever, so I'm limited to what I can do, for now. The question is whether or not I have a blown coolant seal. I've got lots of conflicting evidence, so here it goes.

"Yes" Evidence

Prone to overheating.
Overpressurizes coolant system.
Low coolant buzzer keeps going off.
In "geyser test" coolant flows out of filler neck
Sometimes blows the coolant into the resevoir.
Sometimes I can hear boiling in the radiator after I turn the car off, even though its not blowing coolant out.

"No" Evidence

I don't get white smoke on startup. (Although it is hard to start.)
No constant stream of bubbles coming out of filler neck.
Doesn't drastically fail the geyser test.
Occasionally I can drive for extended periods without any issues except the coolant system being overpressurized.

And I'm not sure what it means, but:

About half the time when I started It feels like one rotor isnt firing.
I also have a pretty bad exhaust leak, and my turbo is leaking oil and needs to be replaced.

Any insights would be greatly appreciated.

 

could be the coolant cap... at least that's one of the least expensive thing you can do that MIGHT solve some of the problems

 

doesn't sound like a blown seal. Try the cap or flush the coolant, it may be clogged in the engine, causing small pockets of water to overheat an boil, causing your problems. I don't know, you could try it. I don't think that "one rotor" start up is caused by coolant, it may be a bad injector/spark plug.

 

yikes, looks like you need to give your car lots of loving, good luck.

 

I had this same problem with my 86 N/A. The exact same problems. I didn't have white smoke comming out of the exhaust either so you know it's not your apex seals. I finally decided to get a new motor. It had 188,xxx miles anyway on the origional motor. When I got my old motor out the coolant seal was corroded so bad the actuall housing was corroded also. One thing you can try is to get your coolant system flushed. Sometimes if you get low on coolant in the overflow tank, it will suck up air. That air get caught in the block, and when the coolant hits it it turns to steam thus overpressurizing the system. If it were me, I'd say it's about time for a rebuild. Good luck.

 

I have replaced the rad cap and thermostat more than once. I also replaced the filler neck, since it looked a little chewed on. That definately helped. Before, it kept spitting coolant into the resevoir, now it just overpressurizes the system. I should mention that the engine has about 5k miles on it and I had a turbo go bad on me since i broke one of the hoses on the waste gate actuator valve and was getting overboost for about a month

 

Do you even know what an apex seal is?

 

OMG whats with the coolant and our cars?

My car almost didn't make it home tonight.
I almost hit the damn H on the temp guage.
The Hose going from my engine to the heater core sprung a leak and I lost my coolant. Luckily I was almost home and still not on the highway.

So my Rex is out of commission for the week.
The good thing though is that I get to drive my dad's Mini Cooper S.

I was so scared when I saw steam coming from the back of my engine.I thought I has blown a big *** seal in the back or something.Then I saw the hose dripping and I was sooooo happy.

Too bad about your car.
I have heard of one definite way to tell if a coolant seal broke.

It's to open the filler cap and see if the coolant coming from the engine has bubbles in it. Bubbles mean compression being lost as it pushes some into the coolant.

Good luck and hope it's something cheap.

 

No bubbles, the coolant does pulse up and down, but my understanding is thats normal

 

There's plenty of tests to determine if it is a blown coolant seal. What I need, if it exists, is one to definatively say that it isnt

 

You're not reporting some of the hallmarks of failed water jackets, so I'm inclined to agree that that isn't your problem (thank your lucky stars if it isn't, btw!)

What is causing this? I don't know. I'd suggest three things:

A) Replace all of your coolant hoses, the primaries to and from the rad as well as the lines to and from the engine/heater core.

B) Replace your water pump. Rebuilt ones are easy to find and relatively inexpensive (and there's nothing wrong with using one.)

C) Do this mod coolant flush:

http://fc3s-pro.com/TECH/MODS/COOL/cooling.htm

But before you do, read this. ALL of it:

https://www.rx7club.com/forum/showth...hreadid=132011

I still stand by what I said in that thread, and I continue to recommend it to 7 owners. My 7's cooling system continues to work perfectly.

With your system being all funky like it is, I'd suggest NOT driving around after you put the flush in - if she starts to overheat again you don't want to be far from home. It might be best if you stay put in your driveway during this. If you are experiencing clogged or constricted coolant passages, I believe that this is your best shot at clearing them short of tearing down the engine...

 

I've replaced some of the coolant hoses, I can do the rest no prob. and i just put in a new waterpump not to long ago. What about the coolant lines to the turbo? Would it help to replace those?

 

Ahh reted's procedure, I tried that once, although i pussied out when it got to 3/4 hot. I guess i'll have to try it again. When I first got the car I had problems with it overheating and replaced the thermostat. the thermostat housing was so caked with aluminum oxide that about half of it was blocked off. maybe restrictions in certain areas are causing pockets to boil, resulting in overpressurization. I can only hope..

 

isnt it true if your coolant seal is screwed you will have oil in your radiator

 

Maybe.

I've had oil (or something that looked a lot like it) show up in my coolant a couple of times. And I've noticed in the 3rd Gen section that oil in their coolant is common. I wouldn't trust that by itself as an indicator of a failing water jacket.

 

And I would think it very unlikely that the build-up was isolated to the coolant filler neck. You probably do have build-up throughout the system. It's mod flush time.

 

Well, I dont' have that engine any more, but there does seem to be a coating of crud in the radiator. One question though, would a "steam bubble" as opposed to an air bubble set of the low coolant buzzer?

 

yeah well i had something "oil-like" in my rad and whenever i pushed my car the least bit near 60-70mph it overheats did a shitty flush and it helps a little but the oilish stuff always comes back but it doesnt seem like im losing anymore oil than what is being injected in the motor

 

isnt it true if your coolant seal is screwed you will have oil in your radiator

 

double post sorry guys

 

I don't think it works inversly. If you do have oil in your coolant then you almost certainly blew a coolant seal, but if you don't have oil in your coolant, it doesn't mean that you haven't, at least according to my extensive searches on the topic

 

'ppreciate the clear up on that yearrgh

 

no problem

 

Flush the coolant system. Make sure you cycle the heat on and off. And make sure you replace the hoses!! Especially the one from the rear of the engine to the heater core....

 

I've never heard it put like that (steam bubble) but I suppose it must. Once that sensor loses contact with liquid (your coolant/water mix) the warning light comes on and the buzz sounds...