2005 Yukon Whine Noise Associated with Tach Speed - HELP!!

[seanstock]

I am not happy. I thought I did my due diligence and recently got a low mileage 6.0 Yukon Denali XL. The engine seems solid as a rock, the transmission seems in good condition also. When I got it, I noticed a drone or w whine at about 1200-2000 RPM. I am going on a long trip and took it to a well respected mechanic. He inspected the vehicle and I had to replace the Oil Cooler Lines, Trans Cooler Lines and the Power Steering Pump. He said that the power steering pump was about to destroy itself and that there was metal contamination in it. He explained that the Yukons have ONE universal hydraulic system so he tried his best and flushed the system multiple times to get it as clean as possible.

I have been driving it for about 2 weeks and I think that the drone//whine has gotten worse you can not hear it from 1100+ RPM and it grows in noise slightly as the revs go upwards. If I am in Park or Neutral the sound correlates with the RPM of the engine. It is not related to the transmission or the speed of the vehicle.

It seems to occur under acceleration (louder) but is still present (albeit quieter) when I am off the gas. Can anyone give me insight into this? I had the belts changed when the power steering pump was done as well as the tensioner. Mechanic says Yukons make this noise, my friend's Yukon XL with the smaller engine (non Denali) and the same mileage and year does NOT make this noise.

HELP????

Link To Video Of Sound

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

 

[iamdub]

I am not happy. I thought I did my due diligence and recently got a low mileage 6.0 Yukon Denali XL. The engine seems solid as a rock, the transmission seems in good condition also. When I got it, I noticed a drone or w whine at about 1200-2000 RPM. I am going on a long trip and took it to a well respected mechanic. He inspected the vehicle and I had to replace the Oil Cooler Lines, Trans Cooler Lines and the Power Steering Pump. He said that the power steering pump was about to destroy itself and that there was metal contamination in it. He explained that the Yukons have ONE universal hydraulic system so he tried his best and flushed the system multiple times to get it as clean as possible.

I have been driving it for about 2 weeks and I think that the drone//whine has gotten worse you can not hear it from 1100+ RPM and it grows in noise slightly as the revs go upwards. If I am in Park or Neutral the sound correlates with the RPM of the engine. It is not related to the transmission or the speed of the vehicle.

It seems to occur under acceleration (louder) but is still present (albeit quieter) when I am off the gas. Can anyone give me insight into this? I had the belts changed when the power steering pump was done as well as the tensioner. Mechanic says Yukons make this noise, my friend's Yukon XL with the smaller engine (non Denali) and the same mileage and year does NOT make this noise.

HELP????

Link To Video Of Sound

I'm betting/hoping it's one of the driven accessories on the front end. First off, check the power steering fluid level. If that's good, stop by Harbor Freight and get a mechanic's stethoscope. Have someone rev the engine until the sound is loudest while you poke around and listen. Be careful not to touch anything moving and be aware that it'll be loud in your ears. But, you should be able to pinpoint it if it is in the front drive.

 

[Scottydoggs]

take the belt off, hand turn all your pulleys and idlers, tensioner, they should all spin smooth, if one feels gritty its bad.

also fire it up belt off. if the sound is gone you know its something belt driven for sure.

 

[seanstock]

I'm betting/hoping it's one of the driven accessories on the front end. First off, check the power steering fluid level. If that's good, stop by Harbor Freight and get a mechanic's stethoscope. Have someone rev the engine until the sound is loudest while you poke around and listen. Be careful not to touch anything moving and be aware that it'll be loud in your ears. But, you should be able to pinpoint it if it is in the front drive.

Well I am going to take the belt off and test the various connections. New PS pump and idler so it could be the tensioner pully.... stay tuned.

 

[iamdub]

Well I am going to take the belt off and test the various connections. New PS pump and idler so it could be the tensioner pully.... stay tuned.

New PS pump, but did they fully bleed the system when they filled it? It could've had an air pocket that purged later, dropping the fluid level. Although, if it was low enough to whine even when not turning, you'd probably have harder steering. Just going through the checklist with the free/cheap checks first. I like the belt removal idea.

 

[rockola1971]

My latest whine similar to the above description was just a bad idler pulley bearing. Replaced and quiet as a mouse now.

 

[seanstock]

OK ..... I'm upset. Replaced the idler on BOTH the serpentine and AC compressor new belts, new tensioners and it's still there. Flushed and bled the hydraulic system still there. Went to two mechanics they oddly said the same thing.. sometimes these just make a whining sound. Well, my friend's 2003 (older) with 180k (more miles) doesn't and is quiet as a mouse, any other suggestions???? The one mechanic said it could be the tranny even if I put it in neutral or park and the noise is there ... I hope to god that is not the case.. HELP it's just annoying as hell.

 

[seanstock]

take the belt off, hand turn all your pulleys and idlers, tensioner, they should all spin smooth, if one feels gritty its bad.

also fire it up belt off. if the sound is gone you know its something belt driven for sure.

The AC tensioner did make some noise so I replaced it but it was not the whine. The mechanic put a scope on all the bearings and pullys and could not find the noise. Uggghhhh

 

[S33k3r]

One of two things is happening: The item that is whining gets under heavier load at certain times, and/or 2) the item that is whining is getting starved of lubricant at certain times. Because of the way these things are built, it is also possible the whine is coming from somewhere unexpected, and being baffled to the location where you are hearing it. You need to look at each of the parts that move at idle. I'd still be looking at your power steering system, if it were me. It is the one thing that really could be doing this even after having been evacuated and updated. Otherwise it has to be something that moves with the engine -- belts, pulleys, tensioners, the clutch fan (assuming you aren't electric). What year is your rig? Edit: I watched the video which has that information in the title; 2005 Yukon Denali XL 6.0. And I am, apparently, REALLY observant, since it is also in the title. :'(

Honestly, it really sounds like transmission whine. The only other thing I could think of is the power steering pump. Does it get any louder/worse, when you are turning to the absolute lock on either side?