Ok my friend has a 89-90 4 door sedan. ( I know where in the wrong section for that but just keep reading) and he swapped in a 95 D15B (JDM) he keeped the stock intake mani and now anti freeze is mixing with the oil. Do you guys think it's just the head gasket or could it be something else? Thanks guys!

 

first guess would be head gasket.
second.... maybe the engine had an aftermarket oilcooler and he got the hoses mixed up.

 

nah everything is stock.

 

Sounds like the head gasket to me. It's pretty much the only way oil and coolant can mix... aside from the bigger problems, like a warped or cracked head or block.

 

Yeah! Ohh well the kid is a hard head and does'nt listen.