Car Problem Reports

Chevrolet Monte Carlo Intake Manifold Gaskets May Leak Coolant or Engine Oil

Chevrolet Monte Carlo Problem
66 Reports
Me Too

Model Years Affected: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

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

Average Mileage: 133,172 mi (10,600 mi - 260,000 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.

  • E.C.G, , 3.8L V6, 123,000 mi

    02 monte carlo ss the upper intake is leakeing water into the oil about the third time in three years .

    Flag This
  • Visitor, , 3.4L V6, 182,000 mi

    coolant leak, bad intake gaskets

    Flag This
  • Visitor, , 3.8L V6, 140,000 mi

    If you want to stop or prevent the problems you see here STOP USING DEX-COOL.
    It was documented in 2007 that DEX-COOL was and still is the cause of the cooling system leaks and gasket leaks. Why you ask? Well to start with DEX-COOL has acid in it. Okay don't believe me, check on it your self. DEX-COOL is an O.A.T. type of coolant. Organic Acid Technology.
    It is the whole reason for intake manifold gaskets leaking.
    I you want to save money and aggravation flush your cooling system and use EVANS COOLANT. It is life time anti-freeze/coolant that has been used in all types of vehicles with no failures in cooling system parts. The main reason is with you DO NOT USE WATER with EVANS. No water means no corrosion and no cavitation which destroys water pumps. Also no water means no chance of freezing and no need to pressurized systems which makes your rubber hoses last much much longer.
    I made the mistake of changing all six of my cars to DEX-COOL about seven years ago. Within three year half of the cars have problems with the cooling systems. I flushed the cooling systems, made the necessary repairs and changed my two classic cars to EVANS and the othe four cars got green Preston. Not one single problem since.

    Flag This
  • Visitor, , 3.1L V6, 96,000 mi

    I had this happen at 84,000 miles and again at 96,000. Both times the head gasket had to be replaced. I traded it in and the dealer said the same thing as the garage. Just too much nickle and diming to have it replaced again. I know things wear out, but ouch. Both times were in the winter, when you want heat pumping through the vents, not an overheated, leaking car.

    Flag This
  • Visitor, , 3.8L V6, 80,000 mi

    anti freeze leak replaced plenim gasket

    Flag This
  • Visitor, , 3.8L V6

    This will be the 3 Intake and gasket replacement. First two the coolant was always low. This time oil is leaking on to the intake valleys and oil level is dropping. Plugs burn excellent.

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

    Intake gasket was changed 2 times on this vehicle between 120,000-130,000 miles.

    Flag This
  • Visitor, , 3.4L V6, 177,610 mi

    bad oil leak

    Flag This
  • Visitor, , 3.8L V6, 260,000 mi

    Engine overheated (x2) replaced rad/ thermostat. Water pump replaced 2 yrs prior. Installed aluminum manifold "elbows" instead of plastic. No visible leaks. Engine will start but rough idle and water flushes back into coolant overflow tank instead of into block making temp rise quickly

    Flag This
  • Visitor, , 3.8L V6, 120,000 mi

    Coolant leaking out of intake manifold gasket onto ground. replaced gaskets.

    Flag This
+ See more reports
Ask a Question