Well I have a 1996 Dakota with Jeep's 2.5L in it, well about a week ago the water pump seized up (bearings came out and seized it) and the belt snapped because of it. Well I replaced the pump and the belt, made sure before I turned it over the belt had no more then 1/4" of wiggle room like I was always told. Well I cranked it and she fired up, great I thought UNTIL the whining noise began. Well I thought it was the belt just needed to break in, so I drove it for a couple days until it became annoying (driving to the sound of the exhaust I can deal with, I love loud cars lol). The noise only happens while idleing or when I step of the gas. Well I took the truck down to a friends garage where he thought it was the power steering pump, nope. I thought if it was a pulley or something if I took the belt of the sound would be gone and we can start from there, turned the truck on and the sound was still there. A few minutes later after I put the belt back on, we took off the air intake tried to find where the sound was coming from, no sound with the screwdriver. So I grabbed a can of brake cleaner and started spaying the engine to see if it was a gasket or something going. Got up to coming onto the injectors she wanted to stall I thought I got some of it into the throttle body so I grabbed my can of carburetor cleaner, shut off the truck and cleaned the throttle body real quick, started it back up and put a piece of cheese cloth over the throttle body to just make sure I didn't get any in there this time, spayed the number 4 and 3 injectors she still ran, sprayed the number 2 and number 1 injectors and she wanted to stall. So tomorrow I'm gonna grab some new gaskets from Autozone or Napa Auto Parts and replace the gaskets (cheaper then replacing the injectors). But has anyone ever heard of a Injector Whining at Idle? Or could it be something else, I'm banging my head against a wall here trying to get rid of the whining noise so I can drive to the sound of Flowmaster with the exhaust out of the bed and the back window open lol.

 

The sound could be the vacuum leak from a bad O-Ring on the injector. Yes replace and see what happeneds. The injectors are labeled to ensure they are in the correct place. And position the same way they came off.

 

Well I replaced the O Ring's on the injectors and it still happened coming from the same area still too, took a can or 3 of engine cleaner, and a power washer and cleaned up the engine. Started looking at it again and come to find out the Intake Manifold Gasket is shot. I gave it a temporary fix for right now by taking a can of liquid wrench and gave the bolts a little more of a turn and it shut it up for now until I can get one on Tuesday. No part stores by my house had one within 100 miles so the repair will have to wait. Hopefully it's a easy fix I know on my Jeep it was a pain in the *** to do. Cause my jeep has a one piece Exhaust Manifold and Intake Manifold.

 

Im glad you found it. Good luck. If you need help we have the service manual in the FAQ in this section.