Les7311

Changed spark plugs a few days back and noticed 3 of the 6 ports with oil buildup.

the plenum was removed back in December to replace Tran, and recently for the Catyl (mechanics)

someone tighten-down the plenum to about 40pounds when they should only be snug. The plenum gasket had oil residue.

where, what could be the cause? Anything to pay attention to? Am suspecting the Plenum to be of age as some lines on the inside seemed cracked

max has 258k miles

thoughts?

PCV? Changed it once about 120k

LtLeary

If the oil is nice and clean under the plemum, is just some residual assembly oil used to help with the seal. If it is black there may be an issue. So, what color is it?

Oil in the tubes is caused ny the seals leaking in the valve cover. Get a new set of valve covers and a bit of black permatex (there are a few places you have to add it to the gasket in some of the corners)

Les7311

—- I would say “recently soaked” and brown - color under the oil cap — the gasket in certain parts had oil collecting so I wiped off plenum.

No leak noticed at the valve covers, did the gaskets about 150k ( now at 258k)