Foam in cooling system, overflowing

Houdini

Houdini

Senior Member
The short story is I'm having problem loosing coolant and found today that it's foaming and coming out the overflow. Found it was down about 1 gallon after about 15 miles driving. I'm using Prestone antifreeze with 50 percent distilled water.

The long story:
When I bought the car about 1 year ago, the previous owner used water only for about 18 years. I decided to use antifreeze and flushed and refilled the car with Prestone and distilled water. Found that my "level" was about at the baffle and didn't see any foam issues. The car seemed to run at 180 or less.

This Spring, I found the car running hotter in colder weather and then I had a water pump leak. So the net of all this is that I bought a new leakless water pump from Snyders and new hoses.

Before installing the new pump, I decided to flush the system. Reading an older thread on the barn, it was suggested to use Evapo-Rust as a good agent to get rid of rust without any acid or harmful effects. So I drained and added 3 gallons of the stuff and run it around the block a few times to heat it up slightly and left the stuff in the car for about a week. When I drained it out, it was pretty black, which is their indicator that it was spent. I then flushed the system several times. I disconnected the hoses and plug the bottoms and flushed the radiator and block separately. Eventually the water became clearer and clearer(less rust color). Next I installed the new water pump and hoses. Then filled with distilled water to check for leaks. No leaks, so I drained it one more time and refilled with distilled water. Then drove it about 15 miles to again check for leaks. I didn't check for foam so I don't know if it did or not. But it ran cooler again. Finally, I drained and filled with Prestone antifreeze and distilled water. Test drove and it stayed cool. After the drive I could not see the water level, so added water slowly till I could see it.

I thought it was just down a small amount and basically wanted to check to see how much it was down by adding water. But it took a gallon. Then I test drove and looked carefully for leaks. No water hose or pump leaks, but then I spotted the overflow leakiing water. At first I figured it was just normal as I filled it close to the top. But when I opened the cap right after I shut it down, it will full of foam.

So I'm wondering if there is still some residual Evapo-rust in the system causing foma when mixed with antifreeze, or does Prestone tend to do that. Since the new pump is probably pumping more efficiently than the old pump, could that be a contributor. This new pump has the cut down impeller.

Is there a different brand of antifreeze that either has antifoam in it, or is known not to foam. I can try refilling with just water, but I prefer to end up with some antifreeze and rust inhibitor eventually.

Are there any automotive anti foam products that can be used. I read where someone used rug doctor anti foam and said it worked. I also have the roofing nail in the overflow, which I put in just before I discovered the foaming problem.

PS: also did a flow test of the radiator and it emptied in about 3 seconds.

Frank
 
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Has your oil level changed? A one-gallon loss in 15 mimutes seems like a lot for overflow. Does the water bubble when the engine is running?
 
I have experienced the same foaming problem when using Prestone antifreeze. I switched to Prestone LoTox and have had no more foaming problems. I have also used Sierra brand antifreeze with no foaming problem.
Prestone is a Ethylene Glycol based antifreeze. Sierra and LoTox is Propylene Glycol based.
 
Seems foaming is generally caused by gases in the coolant system.... maybe something is letting it in --small head gasket leak or something alike... I think a leak down test of each TDC cylinder and listen for bubbling... might provide a clue...
 
Re torque your head bolts, but I really think the problem is your radiator is plugged and the pump is beating up the steam and anti freeze into the yellow foam. Common problem. Try to go 45 mph for 10 straight minutes without boiling. Bet you can't.
Another thing to try is, in third gear, lug it down slow, then give it the gas. If you have a combustion leak into the water jacket, it should bubble out the top of the rad.
 
If you know someone who works with natural gas, you can borrow his combustible gas sniffer, for smelling inside the radiator .or you can buy a test kit from an auto parts store. Or drain and refill with reg water, the run at a high level of water at 1000 rpm and watch for bubbles. You may have a leaking head gasket, or a cracked block. A
 
MAG said:
I have experienced the same foaming problem when using Prestone antifreeze. I switched to Prestone LoTox and have had no more foaming problems. I have also used Sierra brand antifreeze with no foaming problem.
Prestone is a Ethylene Glycol based antifreeze. Sierra and LoTox is Propylene Glycol based.
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Mag,

That is interesting as I am getting some foam in my 31 breather but don't detect any change in oil level . I recently put in a copper head gasket & de-sludged the pan w/ no effect on the breather foam .
This is not my first rodeo w/ a auto moisture leak & automatically think a head gasket or crack but I'm not sure about this ? Temp seems to stay around 160 .
Think I'll try a different antifreeze as per your experience .

Bob
 
Antifreeze is not formulated for non pressurized systems which is why it foams. Sierra Brand antifreeze is what i ran in mine before i had the radiator pressurized- I believe it's also pet safe. But I do not believe it's foaming a gallon at a time and going out the overflow tube. I believe your problem is elsewhere, and you're also foaming the anti freeze. I also would suggest checking your oil for coolant. I wouldn't be surprised of some of the evaporust ate through some of the head gasket.
 
The breather/oil fill pipe can get the white oily mix from several short cool starts and short drives. A thermostat will help to quickly bring the engine up to temp where the condensation gets cooked off.

I've never had foaming from using any antifreeze. You can drain and save the antifreeze, fill the radiator to the top with water, remove the fan belt, and goose the throttle several times while looking into radiator for bubbles. Bubbles will be caused by gases leaking past the head gasket.

Don't run it long enough to have boiling causing the bubbles.
 
You have either a bad head gasket or a cylinder head with a crack. Pulling a cylinder head is a lot of work (for me anyway). You want to do all you can so hopefully you are not going to have to remove the cylinder head more than once. I would do the following:
1. Remove the head and have it resurfaced to be sure it is flat. Have it inspected for cracks using a dye penetrant. Your automotive machinist may be able to do this. Cost me about $100 for this work.
2. Get a new Copper Head Gasket
3. Get a spray can of head gasket sealer at NAPA. Spray all four places, both sides of head gasket, the block surface and the cylinder head.
4. Torque the head down to 55 ft. lbs.
5. Start the car and run for about 5 minutes. Re-torque again. You will find that the torque values will be down 10 to 15 ft. lbs. Start the car and run for 10 minutes and re-torque. Repeat adding another 5 minutes, etc. until you are running the car for 30 minutes, car is a full temperature and there is no change in torque values. I have found that once the head has leaked, it is very difficult to fix by simply re-torquing the nuts.

After all this, years ago I had a situation that I couldn't fix. I got a new old stock head and solved the problem. What a pain. For what it is worth, I would not use anti-freeze for two reasons:
1. When it leaks out the water pump, it goes all over that nice fire wall you have and makes a mess.
2. Using anti-freeze lowers the specific gravity of the coolant and makes it much easier to leak past the gaskets and packing. I use distilled water and anti-rust fluid.

Good luck and let us know what you find. Ed
 
Thanks for all the replies so quickly. The oil looks fine and there is no increased level in the oil. My next step is to drain and put in distilled water, and do what was suggested by revving the engine without the fan belt to see if there are bubbles. Then I may try Sierra brand to see how that performs. I know some of our club members use it, but I didn't see a reason not to use Prestone regular antifreeze, until now.

Do any of you know of a rust inhibitor for the cooling system. Can this be bought in most auto parts stores. Never looked for anything like that so don't know if its commonly available. If I did run just water, I would want that in the mix.
 
Are you using a thermostat?

The Vintage Precision Co. installation instructions for their thermostat and Thermostat Housing include the following advice:

"If possible, it is generally better not to use
antifreeze, it seems to foam easily and blow out of
the radiator making a mess everywhere. Remember,
this is a non pressurized cooling system."
 
In my many years of driving Model A's I have had the foam problem just once. I had purchased a gallon of Prestone and put in my Coupe, properly mixed 50-50 with water. On a steady open road drive at 43-45 mph it foamed badly. As soon as I got home I drained it from the system, bought another gallon of anti freeze this time the Texaco label and no foaming problem occurred with that brand. The Prestone remaining in my system was good and clean so I used it in a more modern car and it did not foam, nor in the many years since the Prestone foamed in my Model A have I ever had foaming again.. In fact I have three Model A's and that has been my only foam problem, one instance in one "A".
 
I do not have a thermostat in the car. I checked the link that Will N had above for Rug Doctor anti foam and apparently its only sold by Home Depot and they said none of the Home depots within 100 miles have it, and they don't order it online. Seems like a hard product to obtain.
 
Houdini said:
I do not have a thermostat in the car. I checked the link that Will N had above for Rug Doctor anti foam and apparently its only sold by Home Depot and they said none of the Home depots within 100 miles have it, and they don't order it online. Seems like a hard product to obtain.
Click to expand...

Houdini-
1) Please add your approximate location to your profile, because what works in some parts of the country are not recommended in others.

2) Carpet cleaners are often rented out by places other than Home Depot. They sell the shampoo and the defoamer there. I use defoamer in my hot tub, so I put a few oz. of it in the radiator of my Dad's car and it stopped the foaming.

3) You really should check for combustion gases in the coolant. I think that's where your foam is coming from, but you need to test it.

4) It is also worth having the inside of your radiator tubes cleaned, to ensure maximum flow. Have it back flushed. If the Evap-o-rust broke things loose, that junk moves to the upper tank and into the tubes if it did not come out when you drained the block.

5) This will be controversial: Your fancy new waterpump may be too efficient for your radiator. Did you grind the impeller down any? :D Sometimes a thermostat will actually help with this (but not if you have a head gasket leak or a cracked head).

6) Yes, regular auto parts stores sell an additive for anti-rust. For example I use 2 little bottles or 1 big bottle and straight demineralized water, no antifreeze, in the summer.

YMMV.
 
AS MAG said. Use low tox' it is pet safe and wont harm paint or babbitt . prestone , has the collie dog the other is sierra. Have fun modelAtony tony white Lafayette, LA Using these will stop foaming.
 
Most of the previous posts speak to the foam issue. I can not respond to the foam issue as I do not use antifreeze. Antifreeze has a higher boiling point than water. Water has better cooling properties than antifreeze. This is my reasoning for using water. However, it is a personal choice as to which one to use.

The big question for me is why are you losing sooooo much coolant in such a short time. Perhaps you are sending the coolant out the tail pipe. This can occur with a blown head gasket allowing the coolant to enter into the combustion chamber and exit out with the exhaust. A blown head gasket or cracked head can also leak compression into the cooling system. This will pressurize your cooling system and force coolant out through the overflow pipe in the radiator. It certainly seems to me that you need to check for a blown head gasket or a cracked head. Hope this helps.
 
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