The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.
Intake Manifold Gasket May Leak Coolant or Engine Oil on Chevrolet G Series Van (G10)
Average mileage: 135,000 (70,000–200,000)
Engine affected: 5.7L V8
8 people reported this problem
1996 Chevrolet G Series Van (G10) 70,000 mi, Visitor
Coolant leak was found to be the intake gasket, The problem my be related to the Dex-cool extended life coolant that will become acidic and destroys the gasket. I would recomend changing the coolant at least every two years this will help prevent but it may still occur.