coolant woes....continuing saga
10-26-02, 05:49 PM
#1
Constant threat
Thread Starter
coolant woes....continuing saga
Well.....shoot.
My coolant system appears to be getting pressurized by engine combustion....maybe.
SOMETHING is causing the overflow to....over flow. And I can't keep the coolant topped off in the AST and the coolant filler neck.
I just went out and started it up and watched it, after topping off the AST and the filler neck, burping it real good, and making sure the levels were right.
Within just a couple of minutes, coolant was coming out from the very front right side of the car, underneath the reservoir.
Now it is just possible (wishful thinking, maybe) that what I have is a cracked reservoir. The damned thing is hard to see, I have the airbox out and the headlight cover off and it is just really tucked way down in there, BUT.....I think I see a crack running along the top, down from the filler neck, about 2 inches long.
The car starts and runs perfect, but twice now in the past week the coolant has run out to the point the "add coolant' light and buzzer have come on.
I guess I will take the undertray of the car off, maybe I can get to that reservoir that way.
Has anyone else ever actually taken the coolant reservoir out?
My coolant system appears to be getting pressurized by engine combustion....maybe.
SOMETHING is causing the overflow to....over flow. And I can't keep the coolant topped off in the AST and the coolant filler neck.
I just went out and started it up and watched it, after topping off the AST and the filler neck, burping it real good, and making sure the levels were right.
Within just a couple of minutes, coolant was coming out from the very front right side of the car, underneath the reservoir.
Now it is just possible (wishful thinking, maybe) that what I have is a cracked reservoir. The damned thing is hard to see, I have the airbox out and the headlight cover off and it is just really tucked way down in there, BUT.....I think I see a crack running along the top, down from the filler neck, about 2 inches long.
The car starts and runs perfect, but twice now in the past week the coolant has run out to the point the "add coolant' light and buzzer have come on.
I guess I will take the undertray of the car off, maybe I can get to that reservoir that way.
Has anyone else ever actually taken the coolant reservoir out?
10-26-02, 05:58 PM
#2
Blow up or win
Take off the tire and the plastic wheel well liner. If you're careful you can bend back just the front portion to get to it. Look carefully for cracks, sometimew they are so hairline on the seams you can miss them. A sure way is put some water in it with red dye (or is it blue) tablets you can get at any hardware store for toilet bowl leaks.
I really can't think of any way to repair it... maybe somebody who does plastic welding can chime in.
It sure would be worth a try 'cause I guarantee you the price of a new one will be shocking.....
I really can't think of any way to repair it... maybe somebody who does plastic welding can chime in.
It sure would be worth a try 'cause I guarantee you the price of a new one will be shocking.....
10-26-02, 06:07 PM
#3
Rotary Enthusiast
Join Date: Feb 2001
Location: Huntington Beach, CA, USA
Posts: 1,025
Likes: 0
Received 4 Likes
on
4 Posts
Before you take everything apart you might want to idle the car while shining a flashlight down the overflow neck, you can see the hole where the coolant overflows like this. That way if its really overflowing you'll be able to see the coolant come up and out the hole, but if you have a crack somehwere else, it'll never make it high enough or start leaking before getting to the hole.
10-26-02, 07:05 PM
#4
Constant threat
Thread Starter
Good advice guys.....
It actually filled the reservoir up, all the way to within an inch or so of the top of the filler neck. And the overflow is at the base of the filler neck.
The car did this once before, right when I first got it.
And putting on a new radiator cap did the trick. I'll get a new one tomorrow and repeat the test. And if it does it again, I think I will get a pressure tester and pressurize the coolant system, see if it leaking down.
Thanks!
It actually filled the reservoir up, all the way to within an inch or so of the top of the filler neck. And the overflow is at the base of the filler neck.
The car did this once before, right when I first got it.
And putting on a new radiator cap did the trick. I'll get a new one tomorrow and repeat the test. And if it does it again, I think I will get a pressure tester and pressurize the coolant system, see if it leaking down.
Thanks!
10-27-02, 01:00 AM
#6
thats not paint....
I hate to say it man but you might need a rebuild.... bad coolant seals show the same symptoms. You can take off that overflow tank easy. Pull off the bottom scuff plate then there is 3 10mm nuts holding it on. For coolant to rush out very quickly like that though.. seems like your getting exhaust gasses in the system from bad coolant seals.
Good luck,
Chris
Good luck,
Chris
10-27-02, 02:37 AM
#7
don't race, don't need to
I JUST went through this on mine...
Don't forget to make sure that the hose running from the overflow outlet you are using (in case you did get rid of your AST) is "vacuum tight". What I mean by this is that there should be no leaks in that line. Starting at the hose end closest to your overflow outlet, I suggest you tie wrap each of the connections this hose makes. Note that there are TWO couplers in this hose before it reaches the overflow tank. Those are the white "gaps" in the hose. Tie wrap them all. The reason for this is: As coolant in your system expands, it will flow dutifully out the overpressure device (i.e. cap at the AST or it's replacement for AST deletion) and into the overflow tank. When the engine cools (like thirty minutes after shutoff!), the coolant inside contracts and this creates a low pressure in the engine coolant system. Now, IFF the overflow to overpressure connection is air tight, coolant will be sucked back into the engine, and all will be well. If the connection is NOT air tight, you will suck AIR back into the engine. This will show up as low coolant after three engine cycles. You'll fill the system up, run it, it'll expand into the overflow tank, causing it to overflow through the black rubber grommet just above the inlet to the tank (pop up your headlight and you can see the grommet... and coolant spilling right out of it!), and the whole cycle starts again.
A fun thing to try is to connect a hose to your overflow outlet and place the other end into a bottle halfway filled with coolant. Mark the starting level on the bottle. Start the engine and let it idle. Soon, you will see HOT coolant begin to fill the bottle (neat to see the temperature differential cause the outflowing coolant to rise to the top of the bottle before mixing with the bottle coolant! But I'm a scientise, and therefore geeky by nature). Let this go for a few minutes, then shut off the engine. Mark the high water level on the bottle. After thirty minues, the level in the bottle should return to original. This shows your system is normal. Further, you can use this technique to burp the coolant system provided the bubbles in the system aren't too large, which they shouldn't be if you filled with the throttle body upper hose pulled off (search for more on this).
OK, that was WAY too long. Just don't immediately assume your engine is blown. I had to replace all FOURTEEN coolant hoses in my system and burp it as I just described before I found out that.. guess what... my engine is JUST FINE!
Don't forget to make sure that the hose running from the overflow outlet you are using (in case you did get rid of your AST) is "vacuum tight". What I mean by this is that there should be no leaks in that line. Starting at the hose end closest to your overflow outlet, I suggest you tie wrap each of the connections this hose makes. Note that there are TWO couplers in this hose before it reaches the overflow tank. Those are the white "gaps" in the hose. Tie wrap them all. The reason for this is: As coolant in your system expands, it will flow dutifully out the overpressure device (i.e. cap at the AST or it's replacement for AST deletion) and into the overflow tank. When the engine cools (like thirty minutes after shutoff!), the coolant inside contracts and this creates a low pressure in the engine coolant system. Now, IFF the overflow to overpressure connection is air tight, coolant will be sucked back into the engine, and all will be well. If the connection is NOT air tight, you will suck AIR back into the engine. This will show up as low coolant after three engine cycles. You'll fill the system up, run it, it'll expand into the overflow tank, causing it to overflow through the black rubber grommet just above the inlet to the tank (pop up your headlight and you can see the grommet... and coolant spilling right out of it!), and the whole cycle starts again.
A fun thing to try is to connect a hose to your overflow outlet and place the other end into a bottle halfway filled with coolant. Mark the starting level on the bottle. Start the engine and let it idle. Soon, you will see HOT coolant begin to fill the bottle (neat to see the temperature differential cause the outflowing coolant to rise to the top of the bottle before mixing with the bottle coolant! But I'm a scientise, and therefore geeky by nature). Let this go for a few minutes, then shut off the engine. Mark the high water level on the bottle. After thirty minues, the level in the bottle should return to original. This shows your system is normal. Further, you can use this technique to burp the coolant system provided the bubbles in the system aren't too large, which they shouldn't be if you filled with the throttle body upper hose pulled off (search for more on this).
OK, that was WAY too long. Just don't immediately assume your engine is blown. I had to replace all FOURTEEN coolant hoses in my system and burp it as I just described before I found out that.. guess what... my engine is JUST FINE!
Trending Topics
10-27-02, 10:39 AM
#10
Senior Member
Join Date: May 2002
Location: Nor Cali, Sonoma County
Posts: 505
Likes: 0
Received 0 Likes
on
0 Posts
To check if your coolant has exhaust gasses in it... just take a ehxaust probe from a smog machine and insert in your coolant.. it will read % hydrocarbons etc... Are you using a "water wetter"?? it helps..Good luck, Carter
10-27-02, 01:30 PM
#11
don't race, don't need to
Actually, if you are filling the overflow but not sucking it back into the system, you may be relatively alright. Check the overflow hose (vis a vis above), then your caps. BOTH should be as new as you can make them. BTW, do you still have your AST? Finally, if you have a pinhole leak anywhere in the system, such as the juncture between a hose and its respective mounting tube, you will not be able to create the vacuum to pull the coolant back into the engine. But all of this is not necessarily indicative of a blown engine, just one that needs a little help in the cooling lines... LOL. Oh yeah, the engine runs stronger when the cooling system is up to par. Kinda neat!
Also, look for rusty colored drip marks down the sides of your hoses and the places they connect to. A pinhole will vent to steam while the engine is running , making location difficult to find. Once the engine cools, the coolant will weep slightly, and over time this will leave residue. Go after those hoses, good man. If you need replacements fast, check out mazdatrix. Thay have ALL of them, can ship them overnight for not very much as they don't weigh a bunch. Happy hunting
Also, look for rusty colored drip marks down the sides of your hoses and the places they connect to. A pinhole will vent to steam while the engine is running , making location difficult to find. Once the engine cools, the coolant will weep slightly, and over time this will leave residue. Go after those hoses, good man. If you need replacements fast, check out mazdatrix. Thay have ALL of them, can ship them overnight for not very much as they don't weigh a bunch. Happy hunting
Last edited by spurvo; 10-27-02 at 01:35 PM.
10-27-02, 02:37 PM
#12
Constant threat
Thread Starter
Okay, all seems to be well now. 
I had a LOT of corrosion around the filler neck, so I carefully sanded that all smooth again, made it look like new inside. And I replaced both the cap on the AST and on the filler neck and.....voila! So far, so good. I have let it go thru a couple of heat-up-cool-down cycles, and it is working as it should be.....(offers sacrifice to the Rotary Gods).
I had a LOT of corrosion around the filler neck, so I carefully sanded that all smooth again, made it look like new inside. And I replaced both the cap on the AST and on the filler neck and.....voila! So far, so good. I have let it go thru a couple of heat-up-cool-down cycles, and it is working as it should be.....(offers sacrifice to the Rotary Gods).
10-27-02, 10:49 PM
#13
don't race, don't need to
MAN, I love dodging this bullet! Way to go, glad there's another happy outcome, given other posts. Takes the life right outta you, huh?
Given that much corrosion, WATCH your cooling system. Ten to one the radiator is filled up with it...
Given that much corrosion, WATCH your cooling system. Ten to one the radiator is filled up with it...
10-27-02, 11:01 PM
#14
Senior Member
I'm with spurvo. Don't just laugh it off and forget about it. Corrosion on turbo rotaries gets out of hand fast if you're not careful because they run so hot.
You're supposed to change the coolant regularly, but if you're like me you're always flushing it because you're working on something that needs you to remove a coolant hose.
-pete
You're supposed to change the coolant regularly, but if you're like me you're always flushing it because you're working on something that needs you to remove a coolant hose.
-pete
Thread
Thread Starter
Forum
Replies
Last Post
LongDuck
1st Generation Specific (1979-1985)
12
10-07-15 08:12 PM
ZaqAtaq
New Member RX-7 Technical
2
09-05-15 08:57 PM