Help, I have a 235 motor in my 11936 Chevy pickup that has about 10k miles on a complete rebuild; I was having some problems with head gaskets & a friend to;d me to put in a bottle of Bars stop leak. The next thing I noticed was I was getting this thick soup out of the overflow tube that appeared like wet concrete that became worse to the point of completely plugging up my radiator. I consulted a local machine shop that says I'm getting oil in the cooling system, but no sign of coolant in the oil; they say I must have a crack somewhere in the block; Therefore my question is, is this diagnosis likely or could it be the result of using the bars leak? What should I do? Sorry this inquiry is so long but just trying to explain the symptoms. thanks for your time & suggestions.
