Can coolant go into the oil pan from a bad water pump on 2000 S10 V6 pickup?

It is possible for coolant to enter the oil pan due to a bad water pump on a 2000 S10 V6 pickup, but it is not a common occurrence. The water pump's function is to circulate the engine's coolant, while the oil pump is responsible for circulating the engine's oil. The two systems are separate but have a few potential failure points where they can intersect.

If the water pump bearing fails and the seal breaches, it can sometimes spray coolant directly into the timing chain compartment, which can leak past the rear main seal into the oil pan.

Another possibility is that a leaking or damaged intake manifold gasket can allow coolant to enter the cylinder banks. If the cylinder walls are compromised by wear or cracks, the coolant can leak into the oil galleys and mix with the oil.

Visual inspection of the engine compartment and the oil fill port should indicate if there is coolant present in the oil. A definitive diagnosis can be obtained through a pressure test of the cooling system or a chemical analysis of the oil.