I have a ? problem with 4AGZE. I have recently cleaned the factory top mount intercooler so it had no oil residue.
Drove it for a day or two and i decided to inspect the intercooler again. To my suprise it had moderate fresh oil residue in the intercooler inlet and outlet.
Would this be just blow-by oil from the cam-covers ?
Seems like a lot would go through if unchecked.