Just installed Rv275 injectors about a month ago and today while the hood was up i noticed a hissing sound or air puffing as the truck idled. Sounds like it is coming from the top of the motor. Sounds like as a injector would fire you would here a hiss or puff sound. Any ideas. Could it be blow-by around the injector(not seated properly) or just the fuel be injected.

 

sounds like you have a injector tip seal leaking , you should be able to see it if you look closely to all the injector and watch for bubbles around the leaking injector. you may even have two seals there from one being left in the hole when you removed the old injectors. get some new coppers seals and replace them.

 

Make a pressure tester and test the integrity of your intake piping. I would guess that there was a intake seal missing or leaking. A pressure tester can be made with a short piece of 4" tubing, two 4" clamps and a 4 inch PVC pipe cap. Thread an air chuck into the pipe cap and fasten it on the inlet of your compressor housing. Then pressurize the system to 3psi, fix the leaks, then pressurize to 5psi, fix the leaks, etc...


brandon.

 

my guess is an intake leak also, my bet is the intake heater grid gaskets since you had to remove it to install the injectors.

 

The truck idles smooth and i dont see or smell any diesel in the oil(oil doesnt seem thin or level hasnt risen on the dip stick). I guess i can pull the valve cover to see if any of the connector tubes are leaking while engine is running. Will also check the intake gasket around heater grid. Thanks for the help.

 

Also check that all the exhaust manifold bolts are tight and that the manifold isn't cracked underneath.