EFIDynoTuning Forum

So im chasing oil consumption through my PCV valve on my 07 4.6 2v. Engine would smoke worse and worse the longer it idled, till were talking clouds. Intake dissasembly revealed oil entering the intake system only through the valve, catch can on breather side of PCV system was dry as well as intake tract in front of the PCV vacuum port.


Motor has big cams so vacuum at idle should be lower than stock, removal of the catch can and replacement of the PCV valve improved oil consumption, but still way off acceptable levels for any amount of idle time.



Threw some nuts in the PCV breather tube near the intake port to act as an airflow restrictor and this solved my issues as far as I can tell for the moment.



Seeing as the motor consumes about the same amount of air as a 5.4 at idle, would switching to a 5.4 PCV valve be the move here?


Motor idles at 756 rpms, no clue what the motor wants to idle at. But figured 756 was easier than 656.

is your pcv hose size different than stock? sounds like you have too large of a hose.

Well its got a non stock intake manifold and non stock engine, so yes.

you may need to add or make the wire mesh baffle, it keeps oil splash away from the pcv valve opening. The pushrod engines have it.

pcv has an optimal velocity that you need to be somewhere in the ballpark of

usually a 3/16 hose about 3 ft long is ideal but depends on vac the engine draws from the cam

if you have two large of a vac line it will suck shut, if its too small it won't evac correctly.