radiator cap leaking?

old_blue

15 Year Member
Nov 3, 2003
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I am losing anti freeze/water and I know it isnt internal b/c I can smell it as I am driving every now and then. Nothing in the overfill but the internals to that long tube in the overfill is gutted... not sure if that makes a difference. I was mostly wondering if the cap on the radiator could be leaking. It was on there when I bought the car. Or is there something wrong with my overfill?? thanks
 
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there is no fluid or anything in the overflow tank? what to you mean when you say there is nothing in the overflow but the internals to that long tube in the overfill is gutted? there should be a tube from the radiator that comes out right next to the cap that goes into the overflow bottle at the bottom. my suggestion would be to go to a parts store (advance auto parts, autozone, napa, pepboys) and get a new cap specifically for your car. i cant remember if its 13 or 16 lbs....but im pretty sure its 13....it will be like 6 bucks. go get one, and try to make your posts a little more clear....not tryin to be an ass, but its really hard to understand
 
i kinda agree with ECU - im not following. ill toss out on other thing. you say you smell coolant while driving and are losing coolant. could be a heater core. but w/o more info, im postulating.

good luck.
 
HAHA you guys are funny, there is a hose going from the radiator to the overflow. the over flow cap is attached to this long tube in the overflow that has internals that kept fallingout so i just yanked them and replaced the cap. I blv these "internals" were for the fluid check light. anyways, the heater core would leak on the inside of the car correct? I dont see any fluid under the car but I dont think it is a big leak regardless. I jsut wanted to know if my cap was bad would it leak fluid out instead of going to the overflow???? thanks for you help I am not sure what more information you guys want b/c this is all I got. thanks hissin for the heater core suggestion but i dont see fluid anywhere inside or out. I think it gets dried up on the radiator when it gets out. but i will run it and see if I can see it coming out .thanks again
 
more than likely, if the cap is bad it will just overflow the coolant resevoir. it will allow coolant to flow out of the radiator when its supposed to keep pressure and the only place for it to go is the overflow tank. if there is nothing in there than its probably a heater core leak. and no, the heater core will not always have a noticeable leak on the inside or outside of the car. i was losing coolant for a long time and couldnt figure out where it was coming from until i decided to bypass my heater core and the coolant loss stopped. never had any coolant drip on the ground or on my floorboards.
 
musclecarfan- I totally agree that was what i was goign to do tomorrow. I was trying to figure it out, stores arent open this late in hawaii or I would have a new cap now and I do blv you are right, i think it goes into the overfill but since it raises the boiling point without that seal then it flows out of the overflow. Yeah i have been running a little bit hotter than normal too but probabl should due to the loss of coolant. when it cools down it sucks it back in but drains the overflow and after a while it will just slowly drain the radiator. new cap coming tomorrow as sson as I get off of work. thanks for your help.

ECU- where does the fluid go then??I have had bad heater cores before and it usually goes somewhere. (not trying to be an azz just curious) if the it is on the inside then usually you will start to get some rust or something on the floor boards. I think I am going to bypass the heater core anyways. Living in hawaii i have not need for it and having it hook up allows that hot water into the passenger side and gets warm on the inside. thanks again, but i think it is the cap being old.
 
the rubber on the radiator cap expans to the point it wont let anythign into the overflow cap...that is what when u need a new radiator cap or so says my friend with a superchard 347 and by the way he is a mechanic...thus i'd reccomend a new radiator cap, they are relatively cheap as state before
 
Well from your post, your only looking at leaks at the heater core, (inside the car) and at the radiatior cap.
I would suggest listening to the above posts and when you take your car for a drive and you smell anti-freeze, shut it down and get under the hood.
It could be leaking at any other hose connection, (12 possible points, in and around there), the water pump,(underneath is a small drain hole), and the radiator itself.
Most proabably the antifrezze leaks out, but it evaporates from the heat of the engine and you can't see it when it cools down.
Get under the hood right after you bring the engine up to operating temp.
Then you can tell if you really need a new cap or need to bypass the heater core.
Just my thoughts.
 
How much are you having to add and how often? It takes antifreeze a good long while to evaporate -- a small amount will sit on a hot surface for quite some time. And, just because you smell it while driving doesn't mean it's not an internal leak. Small leaks into the combustion chamber from a cracked component or a head gasket result in antifreeze/vapor going out the tailpipe - and you can definitely smell antifreeze at the back of the car. If you're adding a lot of coolant regularly, and it's not showing up on the ground under the car or in the carpet -- then it's likely an internal leak. No signs of coolant in the crankcase?
 
Nothing in the crankcase (foam or the like). As i stated before I think it is going out the overflow then when it cools since some was lost out of the overflow it doesnt fill back up. Thanks for all the replies and I will check those other areas too. I am putting new heads on soon (along with other parts associated with the heads) so I should be able to find out if it was an internal leak by then. thanks again
Jon