I cleaned out my intake the other day and before I took it off it's been making this hissing noise from cylinder #8 where the injector plugs into the intake. Well, I changed the intake and I was going to swap back to 24# injectors then decided not to so I put the 8.1s back in. Now, the hissing is coming from #5 cylinder where the injector goes into the intake hole. So, I'm thinking that it is that same injector that is now on that cyliner.

I have been getting a code, forgot the # but it is the egr secondary air injection manfuntion. It is leaking air not fuel and if I turn the injector a little the hissing gets either better or worse. Sounds like one of the o-rings are bad.

I just find it odd that when I first put the injectors in it didn't do it, and now after several thousand miles it has gone bad and making a hissing noise?

What do yall think? Could the egr secondary air injection manfuntion code be the result of this? Anybody had/seen this problem before?

 

o-ring leaking? A good way to tell is if there is dirt on the injector below the o-ring as it sits in the intake. You can also spray carb cleaner or ether on the area where the hiss is coming from while the motor is running and see if you get a hit on the RPM. Sometimes the o-ring will twist as well... which may be easily fixed. You can get an o-ring kit from the dealer... just make sure its the correct o-ring kit for the injector you are using.

Bill

 

Welp, it was the o-ring that is on the intake side of the injector. Nearly half of it was missing! Swapped it out with one of the old injectors o-rings and everything is running fine again.

Cleaned off the injectors too before they went back in.