Intake Manifold Gasket May Leak Coolant or Engine Oil on Pontiac Firebird

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: 132,930 (87,000–243,900)
Engines affected: 3.8L V6, 5.7L V8, V6, V8
7 model years affected: 1993, 1994, 1995, 1996, more1997, 1998, 2001
18 people reported this problem
Viewing 1 - 7 of 7 comments
Almost everyone I know with the GM 3.8 has had this intake manifold gasket fail. I dont know why there are only 7 reports here. There is a mechanic in Portland that does nothing but these repairs all day long for used car dealers
Have antifreeze in the oil! Changing the intake gaskets seem to correct the problem but only last a few weeks and it shows up again on the dipstick!!! Have also changed the lower intake manifold,
Oil in the radiator.
cost me about $375 to get it fixed.
Intake leaking oil. Dripped on distributor so I had to replace it as well. Lasted 20 years so not bad
Engine oil mixed, in radiator fluid
I have a manifold leak