2004 Aztek yellow substance in breather hose

I have a 2004 a stem has 191,000 miles on it. I have already had the intake manifold gasket replaced about 20,000 miles ago. Monday I have to change the radiator. Today I was cleaning the throttle body. Upon tearing it down I took off the intake tube and notice moisture in it. The breather hose that goes from the intake tube to the rear valve cover had a yellowish milky substance in it. It doesn't smell like oil or antifreeze. Plus oil is clean. No milky substance in oil at all. The yellowish substances smells like a smell of your car when it's running like a fuel smell. It smells sweet. I had the intake manifold gasket changed by one of our mechanics at work because I didn't have the time to do it. I have been regretting it ever since because I've had to go back and fix some of his mistakes. Any ideas? It can't be normal or good. Thanks