Hey guys just a question today i checked my coolant and stuck my finger in the radiator and floating along the top is black grease gunk bot not oil what could it be i have no signs of over heating or milky substance in the oil how could i test it ? since i just bought the car i don't wanna be up for alot of money thanks
do a compression check, and take it to a mechanic, they can test for gasses in the coolent, Its the best way to do it.
A lot of times the black or brownish oily deposit is from oil or grease left on engine components that have been replaced. Most mechanics will put a smear of grease on a dry gasket to hold it in place - this grease/oil will eventually end up in the coolant and as oil floats on water it ends up just under the radiator cap.
@ hako looks like that is what exactly happened took it down to the local mechanic he said it just looks like **** and to flush the system then just monitor it as there is no signs of a blown head gasket
