A coolant leak may develop form the Intake manifold gasket causing overheating complaints. The coolant leak may be internal allowing coolant to mix with the engine oil, this condition can result in internal engine damage. Be aware that this problem is often mistaken as a blown head gasket.
Car Problem Reports
GMC Suburban 1500 Intake Manifold Gaskets May Leak Coolant
GMC Suburban 1500 Problem
Visitor, 1990 GMC Suburban 1500, 120,000 mi
actually have an 89 chevy v1500 silverado suburban just did intake manifold gasket solved excessive exhaust issue still have sound of water swishing under hood