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. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.
Average mileage: 146,799 (118,543–192,251)
Engines affected: 5.7L V8, Gasoline
16 people reported this problem
V6-262 4.3 L engine. Service engine code: PO300 random cylinder misfireunder 1,000 rpms while due for LOF. 4 days later started leaking coolant & what looks like light colored oil??? Returned to Pep Boys & advised it's lower intake manifold gasket that needs to be replaced. Next day, informed due to aluminium being eaten away over time (saw the surface damage) gaskets may or not hold, will install gaskets, do pressure test. Other options: manifold resurfaced, used /junkyard manifold OR worst case...a new intake manifold. WRRR (mad cat sound)!!! : (