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Where is the water going?

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regularman

regularman

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I pressure tested the cooling system again today. Put 15 pounds on it for 30 min with no leak down. I even removed the spark plugs to allow more leakage if it was going into a cylinder and nothing, still no leak down. After a drive the water will eventually get low in the radiator and it will overheat. The water never gets low in the reservoir at the pressure cap, just in the top of the radiator and the upper hose will be empty. After I let it cool there will be pressure in the radiator, though it is not very high. I had a motor once that was leaking compression into the water and it did not act like this, in that one the pressure built until the cap leaked water and at the hoses you could feel the pressure. This is not like that. Its almost like the water is not circulating good in one part of the engine and is boiling in there and the water is being changed to steam or vapor real slowly. As long as I keep water in the system it behaves normally, temp goes up when you pull a hill then back down to norm when you get over the top, electric fan comes off and on as normal. I srewed a big funnel into the radiator and ran the motor for about 20 min at fast idle. every few minutes a small bubble of air would come to the top. Maybe something is stopped up and not getting filled with water, Hmmm. This is driving me crazy. I looked at all the plugs and they were tan/reddish as they should be.
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The water has to be going somewhere. It's either leaking out, in which case it should be visible, or it's getting into the cylinders through a blown head gasket, in which case you should be seeing a lot of white exhaust smoke. I suppose it could be leaking into the block, in which case you'd see it in the oil, but I don't want to think about that possibility!

You didn't say how long it takes for the level to drop significantly; maybe it's a small leak you can't see easily or not making a noticeable amount of smoke. I think we can be confident that it's not entering the Twilight Zone, no matter how much it seems like it!
 
Kim, have you checked the heater? It could have a small leak inside the case!
 
Hi Kim,

What kind (Pressure Wise)of pressure cap do you have? It should be a 7lb. at least on my `59 Bugeye 948cc.

You may want to get one of those Pressure Relief Caps as I have on mine.

I`m very int. in your findings as my B/E also climbs up on Temp Guage when climbing a pretty good size hill but no water loss.

Russ
 
Sounds as if we are talking about a crossflow. Are we? If so, I had the same problem. Drove me nuts so I went back to a down flow. Still have some cooling issue's though.
 
No white smoke or fogging, plus that should be seen on one of the plugs I would think. It takes 30-70 miles for the water to get low in the radiator. I have a 14 pound pressure cap which I have tested, but it never comes out of the pressure cap unless I let it get really hot and then shut it off. Its been many years but I recall there was some sort of a problem with the minis that would cause "hot spots" in the head and it would boil in there and not transfer the heat to the water. Oil is fine, under the oil filler cap gives no evidence of water being in there. This is just weird, I wonder if I have a blockage in the head somewhere and the water is just trickling through and boiling off when in a pull and replacing the water with gas, thus leaving the pressure that stays in there that I find a day or even weeks later. Not enough pressure to blow anything out the cap just pressure that bleeds off when I take the plug from the radiator.
 
I'm wondering also whether you have a pin hole somewhere that opens up with heat? your test wasn't long enough for the car to get really good and hot - isd it possible to get the car good and hot and then check?
 
JPSmit said:
I'm wondering also whether you have a pin hole somewhere that opens up with heat? your test wasn't long enough for the car to get really good and hot - isd it possible to get the car good and hot and then check?
Click to expand...
Hey, now that is an idea. I could put the pressure tester on the system and then run it and get it hot and see if anything leaks out then. Also, I am still not sure about my timing. I never had the pointer down there on the timing chain cover, so I just set it by ear. Advanced it to where it started to cut out a bit and then backed off. It seems to run great where its at and no spark knocking. Still if it was the timing then it would just be overheating in the traditional way, not wait till its been run 1/2 hour in the hills to act up. Also, what if I had the wrong water pump, what would the symptom be?
 
Kim,

There are two types of water pumps out there. A question for Frank C. as I don't know the difference. I know he's got a preference. Could the vanes in the pump be worn or the seal and it's leaking out after it really heats up and weeps away but not quickly enough to be visible. Not me field of expertise. I do like the pinhole in the heater theory. Have you shut off the valve going to the heater to reduce and eliminate potential causes. See if it makes any difference.
 
Hi Jim,

"Shut off" the heater valve. I`m going to try that on mine & see what happens just as soon as we get out of this "MONSOON" weather here in the NE!!

Kim, "14lb" pressure cap? Is`nt that a bit "TOO MUCH" pressure? I`d check out whats recommended. My B/E with a 948 stock engine is "7lbs".

Russ
 
That's one way to eliminate a variable. If you find that your Spridget runs on the hot side already this will make it run warmer on those 85-90 degree days but I can open the heater vent doors for warme air and my feet are not being boiled anymore.
 
regularman said:
.... I wonder if I have a blockage in the head somewhere and the water is just trickling through and boiling off when in a pull and replacing the water with gas, thus leaving the pressure that stays in there that I find a day or even weeks later. ...
Click to expand...

Almost certainly not. If the water were turning to steam, unlikely in the first place in a closed system, it would either escape or recondense when it cooled. And, it's pretty hard to imagine a coolant blockage in the head or block, short of a dead squirrel stuck in it--the passages are pretty big.

On the other hand, it's not unusual for leaks to open up when the coolant is hot and close when it's warm. I've seen even pretty big leaks do this.
 
Sarastro said:
regularman said:
.... I wonder if I have a blockage in the head somewhere and the water is just trickling through and boiling off when in a pull and replacing the water with gas, thus leaving the pressure that stays in there that I find a day or even weeks later. ...
Click to expand...

Almost certainly not. If the water were turning to steam, unlikely in the first place in a closed system, it would either escape or recondense when it cooled. And, it's pretty hard to imagine a coolant blockage in the head or block, short of a dead squirrel stuck in it--the passages are pretty big.

On the other hand, it's not unusual for leaks to open up when the coolant is hot and close when it's warm. I've seen even pretty big leaks do this.
Click to expand...
Well its a crack in the head or block then. Hope it lasts until this winter. The cooler I keep it the longer it goes before needing water.
 
[/quote]Well its a crack in the head or block then. Hope it lasts until this winter. The cooler I keep it the longer it goes before needing water. [/quote]

except that if it was, you should have emulsion and I don't think you do.

I am trying to track down a leak in mine right now because something is spraying - the big help is that the cooling fluid spatters and stains - so I can see where it is coming from. Is it worth changing to rad fluid? (you have water now right?) and see if there are stains?
 
just thinking - as I recall money is tight right now but this might be worth a visit to a rad shop to see what they can do with dye.
 
The dye thing is a good idea. I had an annoying A/C slow leak on a car that was found after the dye leaked thru leaving the tracer behind . A ultra violet light lead me rite back to the leak. I dont think it costs very much as I remember and I'm sure you can find some for a cooling system. Its really easy to see the leak just pull it in to the garage.Turn out the lights plug in a ultra violet lite and look for the BRIGHT yellow - green spot.
My father inlaw worked for Eastern Airlines,they would use UV lights to find leaks in airframes back when smoking was allowed on airlines.nicotine would showup in UV. :sick:
 
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