To day as I pulled in my driveway I noticed a high pitched whine coming from underneath the Dak'. The whine wasn't very loud with the truck running but, I could still hear it. I crawled under and had the wife start and stop the engine. There wasn't much of an increase of noise underneath. However, the whine was really loud as the engine shutdown. Could it be my fuel pump?? I replaced the fuel pump on my old S-10 but, it was mostly a low growl when it started to go out. Thanks.

 

Have you wife get in the truck and you go back to the rear. Have her turn the key to the start position without starting it. You should hear the fuel pump kick on to prime the fuel system. That way you can determine if it is the fuel pump.

 

I did that already. As soon as she turned the key on the pump kicked in right away and then went quiet, (I guess as soon as it pressured up).

 

Does it sound kind of like a really big mosquito? I know we've had a few GM trucks where the fuel pumps had a high pitched whine like that, never gave us any trouble it was just a common thing with those.

 

You hit it on the head. That's exactly what it sounds like. So maybe I'll be alright. Of course that's all I'm going to hear now everytime I get in the truck.