Car Problem Reports

Pontiac Grand Prix Intake Manifold Gaskets May Leak Coolant or Engine Oil

Pontiac Grand Prix Problem
61 Reports
Me Too

Model Years Affected: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2006, 2007, 2008

Engines Affected: 3.1L V6, 3.4L V6, 3.8L V6

Average Mileage: 121,733 mi (48,000 mi - 263,000 mi)


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. Our technicians tell us that operating the engine  with a coolant/oil mix can result in internal engine damage. Replacing the intake manifold gasket should correct these leaks.

  • Visitor, , 99,500 mi

    Oil found mixed into coolant resivour

    Flag This
  • p_fultz, , 3.8L V6, 113,023 mi

    Well, when i started my car i saw nothing but white smoke billowing from the tail pipe. Now car the rides extremely rough, i had it towed to a shop and they told me that i needed another engine, but after reading about how common this problem is i think i need a second opinion.

    Flag This
  • Visitor, , 120,231 mi

    The coolant is leaking in to the engine,the intake manifold gasket is being replaced to correct.

    Flag This
  • Visitor, , 3.8L V6, 141,000 mi

    my son checked the oil and it was very low.we checked for leaks everywere.but none to be found.and it dont smoke. noticed milky color in oil cap and radiator cap.most likley head gasket.also has a small skip but thats most likly the water in the oil.also head lights want work on dim.But over all great car that will fly. r ROLL TIDE

    Flag This
  • hotrodgirl, , 3.8L V6, 263,000 mi

    This has been an awesome car with regular maintenance and normal wear/tear replacement parts but after replacing the AC condenser, it will run hot (210 degrees) and the TEMP light will come on. Fans both run, radiator is full. Runs fine in the cooler months and in the hot months (100+ this year)without the AC on. Noticed some oil residue around the opening of the radiator but no water in the oil, no white exhaust. Otherwise still squalls the tires and hugs the corners great. Any suggestions?

    Flag This
  • Visitor, , 3.8L V6, 95,000 mi

    Ruined my cat, had both img's replaced. Common issue with this car.

    Flag This
  • Visitor, , 3.4L V6, 200,000 mi

    car miss-fires up until you get it above 2000 rpm but doesnt miss fire if its been on for awhile replaced the head gaskets intake gaskets all of them it fixxed the problem right up

    Flag This
  • Visitor, , 3.1L V6, 120,000 mi

    Leak from intake under the thermostat housing

    Flag This
  • Visitor, , 3.1L V6, 80,000 mi

    very common problem with these vehicles. GM had a class action suit against them and i was not informed of the suit until it was too late. i should have been reimbursed for the cost of replacing the manifold gaskets but was never notified.

    Flag This
  • Visitor, , 3.8L V6, 123,000 mi

    Problem was not diagnosed until after heater stopped pumping hot air into cabin (coolant was disappearing from cooling system but no leaks external to the engine) and this started ~110000 miles. Between the 110k and 123k mile markers, the cooling system was flushed at which time oil was found mixed with coolant (see problem with heater mentioned above). To fix the coolant/oil leak, the upper/lower intake gaskets were replaced and the problem has not resurfaced.

    Flag This
+ See more reports
Ask a Question