Q: my problems is that the coolant is flowing out the overflow tank. radiator is brand new. water pump is good. what could be the possible problem.car doesnt have anything mixed in the oil and it doesnt smoke out the tail pipe.There no leaks around the engine. all the hose to the radiator are pratically new and ive checked them to see if they were leaking. the needle gets up towards the red after about 30mins but hasnt shut off or started smoking yet.cooling fan works also. 89 mercury tracer with 113k miles. what do u think it could be. k thanks u 2 ill have to check c if i get bubbles going try that tmrrw morning. what the sealer called your talking about? well would the thermostat be causing it to have the coolant flow out the overflow tank or would it be a headgasket is causing it? How hard would it be to change the headgasket. the engine is a 1.6injection if that helps any. okay so i had it pressured checked they did a cylinder leak down test and it should that the cyclinder #2 was leaking compression into the cooling system and they think its a blown-headgasket. so my question is which should i do try the liquid sealer which is what i would like to if it works.
A: If your pressure cap is good, you probably have a leaking head-gasket! If you start the car cold with radiator cap off, (and radiatore full), it will put up steady bubbles, the worse it is leaking the worse the bubbles will "flow"! An occasional "small bubble" is not a problem, as it will push out air trapped inside engine jacekt/head till it has heated up and thremostat has opened.. There is another possibility (did you change the thermostat)? If thermostat changed, did you put it in "right side up"? The "pellet" end (one with the little "wart" around the shaft from top to bottom), -- goes down in water (from engine), - this is the sensor for temperature! Ok back to water, if headgasket is leaking (compression) into water, it will push the water out, - causing the engine to overheat, - causing it to boil rather rapidly after starting engine. It does not have to leak oil into water, or anything into exhaust - depending on how big the leak is, and where the leak is also, (for instance if it is in between cylinders at center of block, there is usually no water present at that exact spot! I would guess that you have still got a small leak in headgasket, and if you stopped as soon as the needle gets near "red zone", - you would probably see the reserve tank full of water but not overflowing yet. If left to "set" for about an hour (depending on how long it takes engine to cool back down - which depends on outside temperature), - the water will be mostly pulled back into the engine again. Water expands when it is hot, - the pressure cap is supposed to let that "extra" volume of water flow back into reserve tank and not be lost "overboard"! Pressure cap,-(most from 8-16 pounds pressure). -- When the water cools down it makes "lower pressure (vacucuum) through the "low" pressure valve back into the radiator. Now my guess is that you were occasionally needing to add water, then needing water more often in increments till it is now to the "overheating problem" it is displaying now! At this point where the gasklet is leaking, and how badly,- is of importance, - it is possible you can still seal it up with one of the chemical products, -- there by saving expense of having head taken off and replace head gasket.--. If you have to replace gasket,- do any maintainance required on head also at this time also, - so you don't end up having to pull head off again and do valve job or something! If you take it to a garage, they have a tester that they put on radiator in place of presure cap, which will allow them to tell if the headgsket is leaking! I learned to do it the way described ("bubbles" system) over 50 years ago, and have been a mechanic ever-since! So I know it worked well enough to depend on!