Intermitent noise

[Ken S]

We have a 2002 duramax under 62,000 miles. At times there is a noise from the front end or engine compartment that is very loud. The pitch is simalar to the wine that the fuel pump makes but 10 tomes louder. Any help would be appreciated.

Ken

[royalglen]

Is it possible that it is the Fan Clutch cutting in??? They can make a lot of noise at times!!

[Ken S]

Not the fan clutch buy thanks.

[DmaxMaverick]

What fuel pump noise are you talking about? You should not hear any fuel pump noise. The only fuel pump (OEM) on the truck is engine driven (or hand operated) and installed at the front of the valley. virtually silent, with all the other normal noises present.

If it is a whine you are hearing, consider the P/S pump, A/C compressor, alternator, idler/tensioner pullies, etc. If you have a CA emmissions truck, the vacuum pump could make some noise. Failing hydroboost units can make noise, but don't get that loud.

Try describing the noise a little better, as well as the running conditions (idle in/out of gear, load, speed, etc.) you hear it, and what changes the pitch.

BTW, Ken:
Welcome to the forums!

[Jim Brzozowski]

With that number of miles, I'd listen with a listening device in my ear around the idle pulleys and belt tensioner. I've seen those make noise for a long time before actually failing to the point you knew for sure that was it. Just be very careful around moving parts.

[copperhead]

Well, I have an intermittent noise that seems to only occur when its hot out and when running at low speeds. When you give it a little throttle then let up there is a squeel, similar to a belt noise but it sounds more like it is coming from the left side front and not from where you would expect if it were a belt, fan clutch etc.