What would cause a 1997 Chevy Malibu 3.1 engine to have an intake manifold anti-freeze leak?
The ’95 and later chevrolet 3.1 liter is known for the lower intake manifold leaks. I am a dealership tech and I believe its a design fault. Every set of gaskets I have replaced have been due to the “silicone inner gaket material” wearing out. The gaskets are both hard plastic, and silicone. on the lower ends of the gasket the silicone surrounds the outer water jacket and follows the head down to the block. What happens is the silicone wears out and allows the coolant to run down the head and exit at the base of the head. New gaskets have been redesigned and are in my opinoin, not prone to this happening.
No answer, but a story – in Aug ’04 had your problem, and intake manifold gasket was replaced. Leaking started again last summer ’06, in the same area you mention. Mechanic warranties work for only 1 year. I should find out where he got his parts, and what kind was used. Maybe the gasket was insufficient. I will call GM, can’t hurt. If no satisfaction, I will take to another mechanic who I know has a more generous warranty.
