hey guys ..it all started when i notice some fresh oil around the valve cover gasket on number 3 of my newtome 95 auto 3/4 cummins. then i heard a very faint hiss hiss hiss sound over the loud engine noise and i think it might be coming from injector 4 or 5. so heres my question, is it possible for an injector to leak a little air by and still work cuz the truck runs like a champ....and if so can a guy fix that problem without buying a new set of injectors? ....if ya'll dont think its an injector could it be hissing from possibly the valve cover gasket leaking area?

 

yeah it could be the injector hold down is loose might beable to retighen them down i would change out the copper seal too

 

 

Sounds like you need a new set of valve cover gaskets. The hiss you hear could also be an exhaust leak there is a gasket right by the injectors.

If it were an injector it should be leaking fuel not oil and it would not run like a champ.

 

this is what i was leaning towards...the hissing is very very faint i wouldnt have even heard it if i hadnt clean my ears out that morning haha i guess gaskets are cheap enough so i will replace em and see where that gets me.

 

Could the breather be plugged up and it pushed the V/C gasket out right there as the pressure found the easiest spot to go?

 

Thats a good point.

If it had an exhaust leak it would be able to hear it pretty easy, I would start where Dusterb318 said

 

does the hiss match rpms?