Groaning noise under the hood from one of the pullies?

Hey guys,

My wife noticed a squealing noise from under the hood when she started her 17 5.7l Tundra. I thought it would be an easy belt/tensioner fix but when I listened to it it's more of a groan. To me it sounds like a P/S pump going out but when you turn the wheel the pitch doesn't change, only when you accelerate. Turn on the A/C no change and I just replaced the belt and tensioner, also no difference. None of the pullies had any weird noises or feeling when I turned them by hand. I have a stethoscope tool to narrow down noises but I can't get to all of the accessories due to the fan and the ones I can reach I don't hear anything out of ordinary. Also, it's louder when you first start it then quiets down some when it warms. The truck has 68k miles and I'm leaning towards the water pump, doesn't leak or over heat. This issue is starting to bug me as I can't narrow it down and I don't to keep throwing parts at it. Anyone have any suggestions or experience with a groaning type noise?

 

I've had a car doing that with the A/C on or off. It was the compressor.

 

Could determine if it's an accessory or pulley if you pull the belt off and start the truck. Not sure if the water pump is driven by the swerp belt on the 5.7 but if it isn't that could narrow that down as well.

 

I had a similar growl on an Element. Did the serpentine and tensioner pulley but that didn't help. Took the belt back off and while listening with a stethoscope hand spun each item. Power steering pump had the noisy bearing. $11 bearing from NAPA fixed it.

 

A good way to check your pullies and accessories is to take off your belt and spin them by hand. If you feel any resistance or notice any noise then the bearings are going bad/are bad. However, you may not always be able to feel/ hear a difference until they are spinning at normal engine rpms. In that case we would use some sort of rotary tool, I personally would us my angle die grinder with a scotch disc to spin the pullies up to speed to detect a bearing growl. A quick and easy way to detect tensioner and idler pully bearing failure.

 

Yeah thanks, that's what I was thinking about trying since I couldn't hear/feel anything with the belt off.

 

Hello. I was just wondering if you ever figured out the source of your groaning power steering pump type noise. I ask, because I have a 17 with the same noise and everything you mentioned as far as warming up and noise disappearing is the same with my truck. It sure does sound like a power steering pump type noise but it’s not. Please advise. Thanks

 

My alternator bearings started to squeal around 60k. Swapped the tensioner and idler pulley before deciding it was the alternator. No issues since.