Car Problem Reports

Pontiac Bonneville Intake Manifold Gaskets Can Develop Engine Oil Leaks

Pontiac Bonneville Problem
62 Reports
Me Too

Model Years Affected: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

Engines Affected: 3.8L V6, 3.8L V6 Supercharged

Average Mileage: 106,156 mi (34,000 mi - 223,000 mi)


The intake manifold gaskets can develop external engine oil or coolant leaks. The intake manifold will need to be removed and the gaskets replaced to correct this issue. In some cases the plastic intake manifold my be damaged requiring replacement.

  • Visitor, , 3.8L V6, 84,000 mi

    Intake manifold leaking oil.

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  • Visitor, , 3.8L V6, 223,000 mi

    Loosing antifreeze from reservoir

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  • Visitor, , 3.8L V6, 137,500 mi

    Service engine light came on at 137500 miles. Car was diagnosed,will be fixed next week.

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  • Visitor, , 3.8L V6, 148,000 mi

    Slight loss of coolant (but no visible external signs). Recent issues with engine "bucking" when warmed up. Diagnosed at shop, will have gasket (s) replaced.

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  • Visitor, , 3.8L V6, 76,000 mi

    Noticed antifreeze level kept dropping. Would only see tiny amount on driveway not enough to explain amount being lost. Checked hoses, radiator, antifreeze holding tank no obvious leaks. noticed moisture on inside of oil fill cap. Went for annual inspection, mechanic found where antifreeze was leaking at top of engine and running onto exhaust burning most of it up before hitting the ground. Found upper and lower intake gaskets leaking. Replaced both

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  • dw26, , 3.8L V6, 97,000 mi

    Coolant was leaking, had the upper intake manifold replaced

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  • Visitor, , 3.8L V6, 90,000 mi

    Oil leak on top of engine from vale covers.

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  • Visitor, , 3.8L V6, 80,000 mi

    I have had a slight oil leak for quite a while, and it seems to correlate with this common problem.

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  • Visitor, , 3.8L V6, 132,890 mi

    Changed the plastic cover and the seal working good

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  • Visitor, , 3.8L V6, 68,000 mi

    Noticed sweet smell at first, then burnt oil on engine block. Rough idle, white smoke out of exhaust. No milky oil though yet. Hoping to get it fixed next week.

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