Foaming radiator over flow

[denver9]

I posted these questions under the existing thread "Water flow" a couple of days ago but that probably wasn't the right place to post it as I got no results. Please pardon the redundancy but I am starting this new thread in the hopes of getting better results.

I have a thermostat in my 31 coupe and have no cooling issues UNLESS I run anything else but plain water. In an attempt to clean the rust out I added a can of radiator flush and followed the instructions. That resulted in immediate foaming and overflow at the radiator cap. I still ran the engine for a while at low speed to flush the system. I then drained the radiator and refilled it at least three times before the foaming/overflow would stop.
After I got the foaming to stop I added water pump lubricant. Once again I got the foaming/overflow. Repeated the clear water flush several times and then added anti-freeze ----same foaming/overflow problem.
Anybody have opinions (although I prefer facts) as to why I am having that problem?

Second question: Have any one of you successfully converted to a sealed system? I am running the Snyder's leak less water pump.

[Mitch//pa]

ck for hydrocarbons in the cooling system

[denver9]

Originally Posted by Mitch//pa

ck for hydrocarbons in the cooling system

Pardon my ignorance, but what exactly are "Hydrocarbons" and how do I check for them and remove them from the cooling system?

[burner31]

Overheating? Have you checked your timing/points?

[Dennis Pereira]

Foaming may also be caused by a lack of anti-foaming agents in the antifreeze. Arctic Blend® antifreeze products include an antifoam chemical in every formula, and each batch is tested before leaving EET’s facility to ensure the ASTM standard for foaming is satisfied. I've heard Sierra brand is anti foaming also .

[Jim/GA]

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Originally Posted by denver9

Pardon my ignorance, but what exactly are "Hydrocarbons" and how do I check for them and remove them from the cooling system?

OK, let me step in here.

Mitch suspects you have a leaking head gasket or a crack in your head or block. Combustion gases coming into the cooling system, and churned by the water pump impeller, will create a lot of foam.

Instead of suggesting that you check for hydrocarbons in the coolant, he should have said check for combustion gases in your coolant.

How to do that? Go to your local auto parts store (I know NAPA carries it) and get what they call a "block test kit". Follow their instructions. Be sure to plug the overflow line for the test.

The test fluid changes color if you have a leak from inside the combustion chamber into the coolant. If you do, then you need to investigate that (pull the head, look for cracks, look for evidence of the head gasket blown out).

If the cooling system passes this test, then I suspect you are sucking in air at the water pump shaft and this is creating the foam. Try to snug up the packing nut. Try adding some more packing. Try a single shot of grease into the waterpump bushing. That sometimes helps stop air going in.

If you have no combustion gases coming into the coolant, but you still have foam, you can add a little defoaming agent to the coolant. Go to a Pool & Spa Supply store. Buy a little bottle of defoamer; they sell it for hot tubs. Put just a CAP FULL (not a cup full ) into the cooling system and it should stop the foam.

I hope this helps.

[Mitch//pa]

Jim here at the shop we use the emissions analyzer to sniff for hydrocarbons a byproduct from combustion, to test the cooling system for head or head gasket issues...

[Will N]

Go to any place that rents carpet cleaners. They sell an anti-foaming additive. A couple of squirts in the radiator, and no more foaming.