Report: Intake Manifold Gaskets Can Develop Engine Oil Leaks
Pontiac Bonneville Problem
Engines Affected: 3.8L V6, 3.8L V6 Supercharged
Average Mileage: 108,181 mi (34,000 mi - 196,000 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, 2005 Pontiac Bonneville, 3.8L V6, 137,500 mi
Service engine light came on at 137500 miles. Car was diagnosed,will be fixed next week.
Visitor, 2002 Pontiac Bonneville, 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.
Visitor, 2002 Pontiac Bonneville, 3.8L V6, 84,000 mi
Intake manifold leaking oil.
Visitor, 2002 Pontiac Bonneville, 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
Coolant was leaking, had the upper intake manifold replaced
Visitor, 2004 Pontiac Bonneville, 3.8L V6, 90,000 mi
Oil leak on top of engine from vale covers.
Visitor, 1995 Pontiac Bonneville, 3.8L V6, 176,500 mi
replaced upper and lower gaskets plemum elbows flushed cooling system changed oil and filter 3 times about $800.00
Visitor, 2003 Pontiac Bonneville, 3.8L V6 Supercharged, 110,000 mi
By the time I learned of the problem with the intake manifold gasket it was too late and had already caused damage. I ended up haveing to replace the crank and bearings. ugh!
Visitor, 1999 Pontiac Bonneville, 3.8L V6, 104,000 mi
Intake manifold gasket failed. So much water entered 3 cylinders it developed hydro-lock conditions as if the engine was seized. Complete gasket replacement for upper and lower intake manifolds was necessary.
Visitor, 2002 Pontiac Bonneville, 3.8L V6, 67,000 mi
The Dextron cooling liquid GM used on all engines was the cause of gasket leaks. GM lost a class action suit on this issue. They would not acknowledge their fault in my case and I had to pay and repair it on my own.