Cooling System Question; Keeps Dumping Coolant Into Overflow
 

The car needs coolant every second or third day. It is puking it into the overflow container, but not sucking it back into the system when it cools.

I have tightened all clamps for the hoses. I have replaced both radiator caps with new stock 13 lb. models. I have had the car on a lift to see if there are any noticeable leaks, and there are none.

This started three weeks ago, and is getting frustrating. I can watch the coolant level through the opening for the top cap (near the thermostat) and when warm, I can see the level change when the thermostat opens and closes. When the level drops (thermostat opening, I think), there are noticeable and abundant air bubbles in the coolant, and they appear to be coming from the direction of the thermostat. When the level rises (thermostat closed, I think), the bubbles are not present.

Any ideas on where I go from here? What should I try?

Thanks, in advance, for your help.

Mark

the internal coolant seals of yoru motor have gone bad, your gonna have to rebuild the motor

The first thing you need to determine is if the internal coolant seals are good. If the bubbles are exhaust leaking past the seals, nothing else matters.


First, get all the excess air out of the system. Try filling the radiator to the top when cool. Start the car and let it run for a couple of minutes. Let it re-cool then refill. Repeat this till the radiator won't take any more coolant. The cooling system should now be mostly burped.

Here is an even better way than the above method: using a Lisle Spill-Free Funnel

http://cgi.ebay.com/ebaymotors/Lisle...spagenameZWDVW


Now on a cold engine, remove the EGI fuse under the hood. Remove the radiator cap. Have an assistant crank the engine. If coolant surges out of the radiator opening, time for rebuild.

If it doesn't, you have a bad cap, a vacuum leak or something allowing the air to enter the cooling system easier than it can suck the coolant expansion back into the system.

Leak-stop type radiator additives can clog the radiator cap vent return; pinhole in the tube from the radiator neck to the overflow tank, slight leak in a thermostat gasket; putting the radiator clamp back onto the old hose in a different position than the original spot; all of these things can cause your problem.

Mine was caused by a crack in the thermostat housing.

Don't believe every rebuild recommendation you read.:lol2:

You should also do a cooling system pressure test. You can rent the tester from Autozone. This may help you find a leak.

is your car and 86 or early 87. There was a recal consisting of a relocation kit for the overflow tank with these symptoms.

Could aslo be a bad radiator cap, or air leak in the overlow hose, or missing the straw that comes off the overflow tank cap, or the overlow hose is plugged into the nipple on the overflow tank cap that doesn't have the straw.

Hey im in KC and am having the same problem, I changed the radiator cap which I knew it was stupid cause it would hold all the pressure in (cause every time it happened, the top radiator tube would be engorged) and sure enough now I have a leaking radiator in addition to my original problem. If you come up w/ anything or U know of anyone in town who can work on them or at least diagnose aproblem let me know and I'll do the same.

Check overheating FAQ. Do what's listed.
Might be too much coolant in system. Let it go to overflow. Siphon out of overflow if it gets too high. If your car runs normal after that, you're done.
Remove radiator cap, idle engine. If coolant bubbles or gushes out, then you may have a blown coolant seal, requiring a rebuild.

I have bad coolant seals and it has the exact same symptoms.
Take off the rad cap then start the car. If you see small bubbles coming up then you have a bad coolant seal.

I would like to know more about this recall. Where is the info, if there was a true recall we should be able to find it. Where do we look.

i have the same problem
 

I have exactly the same problem as you, i went to almost 6 mechanics and they all told me to rebuild my engine .

'Never ask a Barber if you need a haircut."

I would exhaust all options before paying for a rebuild.

Just my opinion.

almost 6 mechanics... so 5 mechanics?

Maybe he meant '6 almost-mechanics' :)

Hell, most everyone on the board would quality under that description, especially me!

Probably just a language thing, since he is from Cyprus.

First Post! WELCOME to the board, Raspa!

Hmm... I'm in this same situation as well... I feel like my radiator may be clogged or something else, and i'm hoping that could do it. It may be a stretch, but I'm counting on it being something like this because i'm nowhere near ready for rebuilding$$$...

My coolant never smells like gas or exhaust...

My car NEVER burns coolant either, so it seems strange... Although I guess if the leak is on a part of the rotor housing that only experiences compression or combustioin, never vacuum, coolant would never have a chance to run in while the motor was running because the pressure would be forcing air out constantly...

Every time I run it, the upper radiator hose is full of pressure, even after the car is off for a while when it cools, the pressure is relieved, but it never makes the vacuum to suck the coolant back in from the reservior.

You can't have "too much coolant". The cooling system has to be completely full, i.e. no air. Over-filling the overflow bottle makes no difference at all.

If you overfill the bottle when the coolant in the rest of the system is full, the bottle will overflow when the car heats up... But thats about it...

You'd need to fill it most of the way up to get it to overflow. I always run my overflow bottle a couple of inches above the FULL line and it never gets near the top. Not that I'd care if it did... ;)