2002 lb7 accessory noise

[Flyboy207]

I just bought a 2002 Duramax with 215K on it. There is a small hum/whine on acceleration through 40-75 mph or so. I was thinking it was low power steering fluid, no such luck, its full. Its not turbo, it fluctuates with how you move the pedal. Any ideas? Also on a sidenote, looking for a real mild tuner for it? Thanks.

 

[CtChevy427]

Have you checked the transmission fluid level?

As far as a tuner I would suggest a Predator. Very simple tuner and a great bang for you buck.

 

[THEFERMANATOR]

PREDATOR and LB7's don't go well together, tend to run REALLY hot EGT's. A PPE economy is a good cheap one to use. Stay away from the EDGE plug in units as they can cause all kinds of havoc with the trucks. As for the noise, you may be hearing the turbo. In 02 they went to the intake with a surpressor in it and they made a different sound than a standard turbo whistle. If you can't duplicate it sitting still, then it is something either load dependant or speed dependant.

 

[Flyboy207]

Yeah the noise isn't the turbo. I'll check the tranny and I think I'll look into that PPE Economy, it looks like what I'm looking for.

 

[Flyboy207]

Transmission fluid is good, I can hear the sound at idle with the hood up, sounds like it's under the alternator.

 

[Pepperidge]

Most likely the idler pulley going bad...it is just under the alternator...

 

[Flyboy207]

That would be a nice surprise considering I thought I was looking at a new P/S pump. That sounds about right though, as the sound doesn't come from the pump. Does the power steering run the hydraboost on the 6.6's also?

 

[Pepperidge]

yes...you can trace the lines to the master cylinder easily...as you look at it from the front of truck the lines go in near the top of the master cylinder just behind the fluid reservoir...