Leaking Coolant from Overflow, but not Overheating

norcalsvt · Sep 21, 2004

Coolant is leaking from the overflow tube. The first time it was dripping out slowly & I suspect while I was driving, because there was a drip line where I turned onto my driveway. Never dripped any more once the engined stopped. Tonight was the second time in a week & there was a pool of coolant when I went back outside after a couple of minutes. Nothing dripping when I opened the hood though. It seems like it comes out of the overflow for a very short period.The temp was around 185 when I stopped the car. Each time Icame home straight from work, around a 15 minute drive on the freeway with no traffic. The fan comes on around 190, so it didn't come on yet. I put in a spal fan, thermostat a couple of months ago & aslo flushed the system. I have a new griffin radiator & water pump that is around a year old. Wondering what is causing this all of a sudden. Could it be I put in too much coolant? I have been trying to top it off lately. The level is usually around the top of the radiator rows & I usually fill it up to the bottom of the neck before it extends up.

What can I check? Most other parts are no more than 1.5 years old.

Ronstang · Sep 21, 2004

Sounds like you have a sightly blown headgasket, you say that sounds funny?...well my Shelby did the exact same thing for a while and it was definitely the head gasket even though upon removal and inspection no breech could be identified. If you didn't use ARP head bolts during the rebuild then do so this time around when you have the heads off.

norcalsvt · Sep 21, 2004

Ronstang said:
Sounds like you have a sightly blown headgasket, you say that sounds funny?...well my Shelby did the exact same thing for a while and it was definitely the head gasket even though upon removal and inspection no breech could be identified. If you didn't use ARP head bolts during the rebuild then do so this time around when you have the heads off.

Is there any way except taking the heads off to check for this? I bought the car after the PO had the engine built & now I do remember the receipt from the builder did say ARP bolt kit

Ronstang · Sep 21, 2004

It is hard to identify when they are only slightly blown because no water gets in the chambers but combustion makes it's way into the coolant raising the pressure enough to blow the cap and leak some fluid. Mine used to only pop and sill ome coolant after driving at highway speeds for a while. You can try one of those blocktesters that check for combustion gases in the coolant but mine didn't whow any but it was definitely the head gasket. I put new gaskets on both heads and the problem never came back. See if your radiator hoses look a little bulged as that can be a sign but they don't always bulge.

gingerbreadman · Sep 21, 2004

Ronstang said:
Sounds like you have a sightly blown headgasket, you say that sounds funny?...well my Shelby did the exact same thing for a while and it was definitely the head gasket even though upon removal and inspection no breech could be identified. If you didn't use ARP head bolts during the rebuild then do so this time around when you have the heads off.

disregard anything this man tells you from now on Im sorry bro but either your out to left field or I am.

Are we talking about the overflow tube that comes out just under the rad cap??? If so i think we need a little lesson on how the cooling system works...

the cooling system is a presurized system, when the coolant is cold there is no pressure, as the engine heats up the coolant expands creating pressure, the rad cap is set on a spring to creat a proper amount of pressure (usually 13ib i think??) when the coolant has expanded enough to raise the pressure above what the cap is set at the cap opens and voila coolant comes out of the overflow tube, the old style was to just dump the coolant on the ground thats why when cold the radiator was always a inch or 2 low, the new system (25 year old tecknoligy now ) is to run that hose to a tank and as the coolant cooled down the system would suck the coolant back into the radiator causing the radiator to be full all the time...

I think there was a difference in the rad caps between the tank and the dump on the ground type system aswell.

basicly it comes down to your car is just fine....

-gbm-

Route666 · Sep 21, 2004

My first thought was the radiator cap not being able to hold the pressure, or filling to the bottom of the fill neck is most likely the cause. All cars I've had equalise themselves to about 1" below the cap.

Ozsum2 · Sep 21, 2004

Quit topping it off!!!! The level should be around 2 inches down when cool.

WORTH · Sep 21, 2004

gingerbreadman said:
disregard anything this man tells you from now on Im sorry bro but either your out to left field or I am.

Are we talking about the overflow tube that comes out just under the rad cap??? If so i think we need a little lesson on how the cooling system works...

the cooling system is a presurized system, when the coolant is cold there is no pressure, as the engine heats up the coolant expands creating pressure, the rad cap is set on a spring to creat a proper amount of pressure (usually 13ib i think??) when the coolant has expanded enough to raise the pressure above what the cap is set at the cap opens and voila coolant comes out of the overflow tube, the old style was to just dump the coolant on the ground thats why when cold the radiator was always a inch or 2 low, the new system (25 year old tecknoligy now ) is to run that hose to a tank and as the coolant cooled down the system would suck the coolant back into the radiator causing the radiator to be full all the time...

I think there was a difference in the rad caps between the tank and the dump on the ground type system aswell.

basicly it comes down to your car is just fine....

-gbm-

I hate it when I agree with GBM , you may just be overfilling it, I've added an overflow bottle and a recovery cap ( the cap is different on a closed system, it has a top gasket where it sets on the top of the gooseneck) to all my old cars, that way the rad stays full to the top and you don't have to guess how much to put in it.

Hack · Sep 21, 2004

norcalsvt said:
Is there any way except taking the heads off to check for this? I bought the car after the PO had the engine built & now I do remember the receipt from the builder did say ARP bolt kit

You probably don't need to do this, but a shop will have a "sniffer" that they can use to check the coolant for hydrocarbons. That's the best way I know of to check for a blown head gasket prior to dissassembly.

ForceFed70 · Sep 21, 2004

I've got to agree with the ugly cookie as well.

If you fill your rad up to the very top, it's gonna puke green when it gets hot.

Pakrat · Sep 21, 2004

well thanks god someone said something, I was reading this thread and wondering what the heck everyone was smoking as soon as I got to this part:

"The level is usually around the top of the radiator rows & I usually fill it up to the bottom of the neck before it extends up".

The top of the rows is a more than sufficient level to fill it at, so what you are seeing is all that excess you keep adding that is not needed when it's hot. Also, if you have not been using a 50/50 mix when you top it off, and are just throwing in more coolant, than this could be making it boil over even a little faster. Coolant actually has a lower boiling point than plain ole water, it is usually added in a 50% mix for the sole purpose of an anti-freezing agent and to in-hibit corrosion, otherwise plain ole water actually would do a better job. Honestly these days it's not so good to have the overflow tube just dripping anyway, but you don't need to replace it with a recovery system either. My advice, drop the level down to the top row, get something along the lines of a tennis ball can, spray it black or whatever if you want and strap it to the side of the radiator. Punch a whole in the lid, add a proper size rubber grommet if you wan't a cleaner look, insert the overflow hose and see what you get in the next week or two. My guess is it will probably be empty, but if not than at least it's not on the ground and you can dump it back in manually. Either way you will know for sure if the problem is solved or not.

Credzba · Sep 21, 2004

Easy Head Gasket Test

Heres 1 link to it, but I just did a google on Head Gasket Test and got a bunch of hits.
http://www.arrowheadradiator.com/head_gasket_or_combustion_leak_test.htm

Basically it is a checmical test that checks for disolved carbon-dioxide in the water.

WAY cheaper and easier than pulling off your heads.

WORTH · Sep 21, 2004

Credzba said:
Heres 1 link to it, but I just did a google on Head Gasket Test and got a bunch of hits.
http://www.arrowheadradiator.com/head_gasket_or_combustion_leak_test.htm

Basically it is a checmical test that checks for disolved carbon-dioxide in the water.

WAY cheaper and easier than pulling off your heads.

Will you guys stop with the HEAD GASKET BS........damn

Ozsum2 · Sep 21, 2004

WORTH said:
Will you guys stop with the HEAD GASKET BS........damn

I got a splinter in my finger. I think I'll cut it off.

gingerbreadman · Sep 21, 2004

WORTH said:
Will you guys stop with the HEAD GASKET BS........damn

actually, its best to be safe then sorry, infact while your at it you might wanna dump the fluid out of the trannie and the rear end and look for gerbals cause you just never know

-gbm-

norcalsvt · Sep 21, 2004

wow. lots of replys, & I guess the verdict. Stop trying to top off the radiator. Btw, it is spilling out of the overflow tank, not that it's any different from what everone was saying.
I'll quit worrying now. Kept me up last night.

Hack · Sep 21, 2004

WORTH said:
Will you guys stop with the HEAD GASKET BS........damn

LOL!

The information about checking for a blown head gasket is still useful, just maybe not to the poster

No need to get upset.

Ozsum2 · Sep 22, 2004

Hack said:
LOL!

The information about checking for a blown head gasket is still useful, just maybe not to the poster

No need to get upset.

It's just that when a problem is diagnosed on here, and you get a poster going 180* in the oposite direction, welllllllllllllllllllllllllllll......................DAMN!!!

WORTH · Sep 22, 2004

The thing I have noticed the most on this board is that not many take the time to try and understand the problem or do any diagnostics before wanting to pull an engine apart. Every problem is not TERMINAL. The first thing you want to do is find a simple solution that doesn't cost anything, if that fails go on to more.

Most problems are SIMPLE. Start with the basics before condeming anything.

There are a lot of people here who know nothing about their cars, and because of that do not explain their problems properly, take the time to ask some questions and find out what the actual symptoms are before making a diagnosis.

mozpony · Sep 22, 2004

you can't fill your rad. to the neck if you aren't using a catch bottle the coolant expands when it gets hot and if there's no room in the rad. it has to go somewhere.

Leaking Coolant from Overflow, but not Overheating

norcalsvt

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Ronstang

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norcalsvt

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Ronstang

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gingerbreadman

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Route666

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Credzba

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Ozsum2

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gingerbreadman

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norcalsvt

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Ozsum2

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