how do I replace a thermostat in a 97 pontiac transport?
and how do I know thats what I need to do? my overflow coolant cont. is really oily and sludgy inside what does this mean?
The thermostats in your trans sport may be a little hard to replace depending on how cramped the engine bay is. This should set you on the right track -
http://www.autozone.com/az/cds/en_us/090 0823d/80/04/d1/f0/0900823d8004d1f0/repai rInfoPages.htm