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.
Car Problem Reports
Chevrolet G Series Van (G20) Intake Manifold Gaskets May Leak Coolant or Engine Oil
Chevrolet G Series Van (G20) Problem
Engines Affected: 5.7L V8, Gasoline
Average Mileage: 123,486 mi (107,000 mi - 150,459 mi)
Visitor, 1994 Chevrolet G Series Van (G20), 5.7L V8, 107,000 mi
Saw coolant leaking from front of manifold.
removed manifold, found more leaks between head gaskets into oil.
replaced with new gaskets, problem solved.
Visitor, 1994 Chevrolet G Series Van (G20), 5.7L V8
I have gotten a leak from the radiator and the intake gasket (outside) Radiator repaired and hoses . Did not bother with the small leak of the intake manifold
Visitor, 1993 Chevrolet G Series Van (G20), 5.7L V8, 113,000 mi
breather grommet went first. easy fix.then intake gasket along with manifold gaskets...though manifold may have crack in it...wont know until it is pulled. hear these vans have manifold cracking issues (darnit. Already replaced transmission at 112k. Also, rear diff seals shot and have to replaced. Happy Trails.
Visitor, 1990 Chevrolet G Series Van (G20), 5.7L V8, 150,459 mi
really its 1988 but yeah im thinkin about do all gaskets since coolant n oil is mixed SMH