I've been outside all day working on my car.
It's a stock 1988 RX-7.
The last time I drove the car, when I stopped there was coolant steam coming out from under my hood. I called for a fire extinguisher and opened it up and there was a small coolant fire on the top of the manifold.
Today, I examined all the radiator hoses, and noticed one (the upper main) that was squirting coolant out of a pinhole leak right by the elbow that goes to the fill cap and it was shooting straight at the manifold.
At this point I thought the problem would be solved with an obvious cause.
I refilled the coolant, then I replaced the hose and started starting up the car to test whether there were any leaks under pressure. I was starting it up for about minute long periods, and there was no steam, and the coolant level at the fill cap, radiator cap, and overflow bottle remained constant.
Then, I reassembled everything I took out to replace and inspect the hoses (airbox and friends) and tested the car for about a 5 minute period, putting it into gear and backing up to where the ground is more level ( I live on a hill.)
I looked under the car to check for coolant drips and there was nothing that I could see.
Then, I pulled it back over to it's parking place, and here comes the steam again. I shut the car down, and examine it. the smoke appears to be originating from the underneath and around the exhaust manifold, and now it's coming out of one tailpipe as well.
It only seems to be burning coolant wherever when the system is fully pressurized.

I'm only moderately experienced with problems like this, so I'm not sure what it could be.

Blown engine? one of the small heater hoses leaking on the manifold? some hidden hose I can't find?

Any input would be appreciated =/

 

is it a turbo? if so the coolant to the turbo might be leaking.

however I think it might be air in the system; I dont wanna jump to a blown engine right off the bat. how quickly does it heat up from cold? do you see any bubbles in the resivour?

 

It's naturally aspirated..

I was seeing bubbles when I had the pinhole leaking hose, but after that was replaced that seemed to stop the leaking and the coolant level stayed constant.
But there might be air inside from then.

I'm going to sound like a real gigantic moron, but how do I bleed the coolant system? I'm unsure if I bled it correctly. Can you think of a way having air in the system would make coolant steam come out of the manifold area? =/ Is there any FAQ's or anything like that on coolant system bleeding I can read?

 

pretty much just run the car with the upper cap off and with the heat on until you dont see any bubbles, it will most likely flow out the top, which is fine, just let it flow out...one u dont see any bubbles and the coolant at the top of the neck is warm, you are golden

 

I'll give that a try, hopefully it will clear things up.

 

I gave the system bleed a try. I ran it about 5 minutes with the heat on and the upper fillcap off, letting the coolant flow out until the coolant at the neck of the fill cap was warm.
I had no smoke or problems, so I put the cap back on and ran it for 5 more minutes to test it out. It ran well, and there was no smoke anywhere.
Near the end of the 5 minutes the fill coolant buzzer came on.
I turned off the car immediately, cause low coolant is bad.

I checked it and the coolant is still level with the neck of the fill cap.
I'm really perplexed with this whole issue, any suggestions again? =/

 

make sure its full of coolant...make sure the sensor on the rad is tight. and make sure that your res. is between the lines

 

Are you saying that the coolant was on fire? I don't thnk so. Maybe fuel leaking from a failed pulsation damper on your primary fuel rail would be more likely. Do a search for pulsation damper and you will find gobs of information on engine fires caused by these little buggers.

 

all I know is there was a little small fire on top of my manifold =/
I just assumed it was coolant since there was burnt green junk and pooled coolant all over it..

 

Ummm...I'm pretty sure that coolant can not burn.
Evaporate, yes.
Change to steam, uh-huh.
Burn...not so much.

Unless you got your water from the Cayahoga River.

 

can you think of any way the leaking fuel from the pulsation dampener would cause the coolant steam coming from the manifold, and the tailpipe the last time , and also the seemingly false low coolant warning, or do you think the problems are unrelated?

 

I read up on dampener problems, but I know from looking at my mainfold that there's no copious amounts of fuel, it's been dry save for the coolant that was sprayed on it.
I've looked at it after the tiny fire that happened when I was driving it for a longer time, and after I've tested it for short periods it is dry.

Would a faulty dampener continually leak, or only under certain conditions?
Because this leak and fire only occurred when the coolant problems have been happening.

Thanks for your input, guys, I'm appreciative of your help..
It's probably annoying to get asked millions of questions from ignornant people like me, but I hope to get through this with a little help and hopefully learn a bit from it.

-T

 

My guess would be that you're dealing with a couple of unrelated issues. Unless some combustable material like wiring insulation was what was burning, I would pursue the PD possibility. Would a PD leak all the time? I don't have an answer for that. Maybe someone else does.

If you definitely have coolant vapors at the tailpipe, you almost certainly have internal coolant seal problems. Does the vapor smell sweet? If not, it probably isn't coolant vapors. Maybe just condensation in the exhaust system which would eventually go away when the system warms up. Or perhaps fuel-oil smoke. A little sniffing should tell you the difference.

As far as the low coolant warning light, maybe the wires to that sensor shorted out.

 

I went to recheck the car today after it has been sitting for a week.
(I work and goto college during the week)
I took off the top filler cap and the a little coolant came out as if it were still pressurized. It was all the way to the top, and looked like none had leaked out.
So, I guess I fixed the leaking coolant problem.
I'll do a little testing tomorrow to see if I can determine if the pulsation dampener is causing the smoking.
I want to clean the top edge of my manifold before I test it out, so no coolant or oil or other crap will be on there, which will make it easier for me to see if it's covered in fuel.
Can anyone recommend a cleaner for this?
I'll probably scrub it with a toothbrush.

 

I did another test run today. I warmed the car up for about 10 minutes with the heater on, and everything was fine. I moved the car forward and back, to see if motion/ angle of the car would do anything.Still nothing. Then, after about 15 minutes, I noticed a teeny wisp of coolant steam coming from the area of the engine above the manifold. The manifold is not wet, and the car is not losing coolant or smoking from the tailpipes anymore. It seems steam is escaping from somewhere in that region of ..objects clustered above the manifold. The smoke seems to be strongest by the device that has the heater hose going into it.

I really don't know much non general mechanical knowledge about all the heater and cooling system equipment, so any help or advice would be appreciated.