Blown head gasket

My 97 Camry LE I4 was looked by a toyota dealer in December 2003 and I was told that my head gasket was blown. They told me that my engine oil was like glue and that the total would be about $1000. However, I have been driving the Camry for the past 3 months with very few problems. I never had the head gasket replaced becaus my parents mechanic told me that the head gasket leak was external which explains my oil looking like glue. If any of you are familiar with the engine the oil solidified about 6 inches down from where the exhaust manifold meets the engine. Recently (within the last two months) while driving my routine roads, there is this very low gradient hill that i drive on daily. And while i drive on it @ 50-70 mph my air vents circulate this sulfur-like smell throughout my car. I would like to know is this is related to my head gasket at all. Also, my car idles at 2000+ RPM for about 5 minutes whenever i start it up. And while i start it up a puff of white smoke comes out of the tailpipe. Another problem with my car is that the transmission seems to be slipping (especially 1st gear). I have an automatic. My car seems to be bucking all the time. And last but nut least, The container for the coolant in my engine compartment is BLACK as well as around the edges of engine block and along the entire front of engine. Is this serious? Please help me out here. Thanks alot!

the head gasket leak isn't external if you have oil in the coolant, coolant in the cylinders(white smoke), coolant in the oil. if it was my car i wouldn've changed the head gasket right away coolant will destroy engine bearings, contaminate oxygen sensors, catalytic convertor and all those things cost money. the high idle is probably because oil in the coolant screwed up the ect(engine coolant temp) sensor or you have an intake gasket leak. check the fluid level in the tranny it might just be low and change the fluid/filter sometimes the filter screen gets clogged. i'd say this is serious. what i would do is get it fixed imediately. hopefully the engine can still be repaired by just replacing some gaskets and sensors. if worse comes to worse you might want to look into geting a used engine from a wrecker and swap it in. get this car fixed asap or look into buying a bus pass