white foam poped out of coolant resiovor overheated

I was heading home and the car over heated on me on the freeway. Was one exit way so i keeped going with heater blasting. When i got home the resiovor cap blew off and their was this white rocks . When i touched them they crumbled. Than i found a nice chunk which looked like foam. Wouldnt crumble. It looked like real foam. I'm triping out hoping its not my Head Gaskets! No smoke, no gas or coolant in oil YET that is

Any ideals

I have a 180 stat with fan trick and a FMIC with no fans. And was a cool day today.

EDIT: Its not foam like foaming when you beat egg white and getting all foaming. Like piece of foam from packaging. And the rest where like little rocks that crumble.

never can tell -don't have to have water or coolant in the oil for a blown head-gasket and if they did'nt they soon will

you'll need to figure out why it over-heated, sounds like the rad needs to be cleaned-out, or replaced, if crap is floating around in there

maybe think about installing a real temp gauge, to keep a better eye on the temp department, if it happened once it will do it again...at the first signs of over-heating get the car off the road in a safe place and let it cool down, never open the rad when it's hot like that, you can get burned pretty good if the water/coolant gets ya - but don't drive the car if it's over-heating -it will cost you

Definitely change the coolant and flush out the cooling system really good. There has to be a reason why it overheated, so don't put it all back together until you find that reason. Sounds like you have blockage somewhere. I'm thinking those white rocks are smething used to to temporarily fix a coolant leak. They may have caused a blockage in the system, hard to say. I know radiator shops can check your radiator to make sure it is working properly.

The way most radiator shops check a radiator for flow or blockage is this.

They fill the radiator to the top with a water hose while holding your hand over the lower output (with the hose off of course) take your hand off and it should flow out the diameter of the hose, and a stream about 6" from the radiator.

Not sure if there is a better way than this, but it's worked for me over the years.

That foam was probably the float for the coolant level indicator coming apart from excess heat. Either you popped the head gasket or the cooling fan stopped working.

You should have pulled over and shut it down. Chances of warping a head when overheating are high.

The temp went down as soon as i hit the heater thats why i keeped going. I'll be flushing it and go from there.