Anti-freeze smell in cab

A couple of days ago I started smelling anti-freeze in my truck(only in the cab). I also noticed that my temp. gauge was higher than usual, actually it was jumping up and down. I had my heater core replaced last year, becuase I was smelling anti-freeze in the cab and the windows were foging up. I had my water pump and thermostat replaced about 4 years ago. So anybody have any ideas what could be wrong? Oh, yeah I put water in it yesterday(about 20 Oz.) and when it came to the top it was brown.

Thanx, in advance

Rob

hmm sounds like oil in the gas and its fuming inside the cab. see if the oil is milky

Agree with james...sounds like you've got a head gasket or something that is leaking.