2003 Pontiac Grand Prix Oil leak from on top or near the to

LARRY HUSTON

MEMBER
2003 PONTIAC GRAND PRIX
6 CYL
FWD
AUTOMATIC
76,000 MILES

3.8 Liter, non turbo. The engine has an external oil leak somewhere near the top of the engine. I do not see any main seal leakage from the crankshaft or oil pan or tranny, transaxle, powersteering, etc.
I cannot find the leak, but there is pooling of oil in some of the boss holes near the valve cover gaskets. I have torqued most all the bolts on the valve covers; those I can get too wiithout taking parts off the engine. The oil is still leaking. I suspect valve cover o-ring seals, but maybe you know of something else, like maybe 0-ring seals on the fuel injectors. I cannot determine if any injector is leaking oil without taking off parts or pieces. Any other source where oil can seep and run down the side of the motor would be helpful. The oil fill cap is not leaking.

Is there a PVC valve that requires service, where internal engine pressure is blowing oil out some seals? If so I cannot locate it.

The car runs fine and adding oil between changes at 2000 miles is not necessary, but the engine block is "wet" with oil and when parked in the garage, drips oil onto the floor. Any help would be appreciated.

PS: A 3.8 Liter Buick, 2001 is doing the same. Help if you can. Thanks, Larry

1 Reply

MMPRINCE4000

MECHANIC
8,548 POSTS

I would suspect that the valve cover gaskets are leaking, or possibly the lower manifold at the valley. The valley is sealed with RTV and it is possible it could leak there.
There is no oil source for the fuel injector o-rings, if they are bad you would have a vaccum leak or fuel leak.
The PCV valve is under the MAP sensor on the right end (passengers) of the upper intake. You have to remove the MAP sensor assy. To get access to the PCV valve.
You can have a garage put some dye in the oil, drive it for a week then take it back and have them look at the engine with a black light to isolate the leak.