whining noise

pm26 · June 3, 2006

I hear this faint whining noise when I drive my truck at low speeds and accelerate from zero speed. The noise increases slightly with engine RPM. At first I thought that it was coming from the transmission, but now I think it is either the alternator bearing or one of the idler pulley bearings on the serpentine belt. The noise disappeared for about 1000 miles and it recently came back. Anybody has experienced anything similar?

Are alternators in these trucks prone to making whining noise?

I talked to a GM tech who rebuilds transmissions at the local dealership, and he told me that 4L80 transmissions tend to whine in the first gear and that is supposedly normal. I have a 4L60 transmission in my truck. He said that he has never heard whining from one of those. I hear the whining in neutral, park, and also in second gear if I accelerate slowly. It is engine RPM related and it surely sounds like a bearingin the engine compartment, most likely alternator bearing. If I remove the serpentine belt, will it hurt to run the engine for a few seconds without the alternator to see if the noise disappears?

LINCHPIN · June 3, 2006

I hear this faint whining noise when I drive my truck at low speeds and accelerate from zero speed. The noise increases slightly with engine RPM. At first I thought that it was coming from the transmission, but now I think it is either the alternator bearing or one of the idler pulley bearings on the serpentine belt. The noise disappeared for about 1000 miles and it recently came back. Anybody has experienced anything similar?

Are alternators in these trucks prone to making whining noise?

I talked to a GM tech who rebuilds transmissions at the local dealership, and he told me that 4L80 transmissions tend to whine in the first gear and that is supposedly normal. I have a 4L60 transmission in my truck. He said that he has never heard whining from one of those. I hear the whining in neutral, park, and also in second gear if I accelerate slowly. It is engine RPM related and it surely sounds like a bearingin the engine compartment, most likely alternator bearing. If I remove the serpentine belt, will it hurt to run the engine for a few seconds without the alternator to see if the noise disappears?

<{POST_SNAPBACK}>

Is it coming from the rear? Normally if thats where the whining is, its the fuel pump. But if its kinda loud it my be going out. Once those fuel pumps go, there is no starting up. Mine on my 97 Suburban make this whinnie noise, but its not to loud.

Now, if its not in the rear, I'm sorry for the misinformation

ken1mod · June 3, 2006

I hear this faint whining noise when I drive my truck at low speeds and accelerate from zero speed. The noise increases slightly with engine RPM. At first I thought that it was coming from the transmission, but now I think it is either the alternator bearing or one of the idler pulley bearings on the serpentine belt. The noise disappeared for about 1000 miles and it recently came back. Anybody has experienced anything similar?

Are alternators in these trucks prone to making whining noise?

I talked to a GM tech who rebuilds transmissions at the local dealership, and he told me that 4L80 transmissions tend to whine in the first gear and that is supposedly normal. I have a 4L60 transmission in my truck. He said that he has never heard whining from one of those. I hear the whining in neutral, park, and also in second gear if I accelerate slowly. It is engine RPM related and it surely sounds like a bearingin the engine compartment, most likely alternator bearing. If I remove the serpentine belt, will it hurt to run the engine for a few seconds without the alternator to see if the noise disappears?

<{POST_SNAPBACK}>

Is it coming from the rear? Normally if thats where the whining is, its the fuel pump. But if its kinda loud it my be going out. Once those fuel pumps go, there is no starting up. Mine on my 97 Suburban make this whinnie noise, but its not to loud.

Now, if its not in the rear, I'm sorry for the misinformation

<{POST_SNAPBACK}>

ken1mod · June 3, 2006

I hear this faint whining noise when I drive my truck at low speeds and accelerate from zero speed. The noise increases slightly with engine RPM. At first I thought that it was coming from the transmission, but now I think it is either the alternator bearing or one of the idler pulley bearings on the serpentine belt. The noise disappeared for about 1000 miles and it recently came back. Anybody has experienced anything similar?

Are alternators in these trucks prone to making whining noise?

I talked to a GM tech who rebuilds transmissions at the local dealership, and he told me that 4L80 transmissions tend to whine in the first gear and that is supposedly normal. I have a 4L60 transmission in my truck. He said that he has never heard whining from one of those. I hear the whining in neutral, park, and also in second gear if I accelerate slowly. It is engine RPM related and it surely sounds like a bearingin the engine compartment, most likely alternator bearing. If I remove the serpentine belt, will it hurt to run the engine for a few seconds without the alternator to see if the noise disappears?

<{POST_SNAPBACK}>

I notice a whine from my 2000 5.3 in warmer weather, if yours is warm weather related it might be the cooling fan clutch engaging for more cooling. that is what it is on mine and it is definitely noticeable.

Ken

Is it coming from the rear? Normally if thats where the whining is, its the fuel pump. But if its kinda loud it my be going out. Once those fuel pumps go, there is no starting up. Mine on my 97 Suburban make this whinnie noise, but its not to loud.

Now, if its not in the rear, I'm sorry for the misinformation

<{POST_SNAPBACK}>

pm26 · June 3, 2006

My truck does not have any fan clutch. It has electric cooling fans.

I am quite familiar with the whining noise an engaged fan clutch makes. I had one in my 95 Nissan pickup and when it engaged it was definitely audible. The noise I am hearing in this truk is there even upon a cold start.