Posted 3/2/2021 23:45 (#8869397 - in reply to #8869052) Subject: RE: Ford 6.0 Powerstroke Engine Oil Additive Question
IL
The hissing sound at idle is probably just the exhaust back pressure valve closing to put a load on the motor so that it warms up quicker. If its kicking on while driving or after the truck is warmed up you can hot wire it to a dash switch.
Ford 6.0 Powerstroke Engine Oil Additive Question
