I have already checked and there is no water on the oil. Oil is a fresh and clean as when i changed it.
Brand new headgaskets/rebuilt heads. they have less than 2 hours run time. Entire cooling system including heater core is new, replaced same time as head gaskets.

I have 2 opinions:

There was a crapload of stop leak in the car when I bought it, could this just be remnants...

or..

It has been sitting in the garage for several months with just water in it, no coolant. Could this be rust/scale deposits??
This is what I'm thinking.

I idles the car for 30 minutes today while I ran some Permatex radiator flush(the stuff with the hydrocloric acid in it) and it did'nt overheat.

Tomorrow I am going to pull the plug on the side of the block, drain the block, and then lossen the lower radiator hose and re-flush the system with some water.

 

At the top of the hole it looks like scale rust, wrong color though. The color looks like someone dumped a bunch of stop leak in it. If your radiator and heater core are new you are on the right track flushing out the system with some good acid based flush. When ever I flush I pull the top hose off the radiator and stick a garden hose right in the radiator and start the car, let it run until it looks like clean water coming out the hose. You might have to run some more flush after doing this and repeat the whole process because that looks bad!

 

Yeah, that foam is only in the top 1" of the radiator. if you stick your finger through it you get clear water.

I can never remember if the water goes of the radiator thru the top or bottom hose??

 

 

thanks, that very helpfull!!!!

 

4playta..I did as you described and it is much better in there!! Foam is gone..
thanks.

 

You had some nasty looking crud in there, my guess would be stop leak...I would put another bottle of flush in there and drive it around for a while and repeat the whole process again.

PS: Forgot to add make sure you turn your heater on when you do this to clean the crap out of the heater core *** well.