Here's why it's difficult to find a specific history:
* Varied Engines: Pontiac Montanas used different engines over their production run. A leak in one engine's intake manifold gasket would not automatically mean the same would happen in another. The problem would be engine-specific, not Montana-specific.
* Scattered Reports: Reports of intake manifold gasket leaks (leading to coolant in oil) would be scattered across owner forums, mechanic records, and perhaps some less-accessible internal GM service bulletins. There's no central, easily searchable database compiling this type of specific failure data across a particular model.
* Other Failure Modes: Coolant contamination in engine oil often points to more serious issues like cracked cylinder heads or head gasket failures, which might overshadow reports of less severe intake manifold gasket leaks in the same vehicle.
* Age and Condition: The likelihood of an intake manifold gasket failing increases with the vehicle's age and the condition of its maintenance. Older vehicles are more likely to experience this, and accurate historical data on maintenance practices across all Montanas is impossible to compile.
In short: While a Pontiac Montana could suffer from an intake manifold gasket leak causing coolant to mix with engine oil, it's not a historically notable or unique problem for this minivan compared to other potential engine failures or problems experienced across various makes and models. If you're concerned about this, it's best to check owner forums specific to your model year and engine type, or consult a mechanic.
