My 03 GMC Yukon Denali XL started making a 'whirring' sound that speeds up as I...

[butter_cream1981]

...accelerate, then when...? I take my foot off of the accelerator, it makes a noise like if you had a card in a bicycle wheel spoke. It makes this sound on the driver's side. I also noticed that after the car warms up good, the sound mysteriously disappears. What could this be? Also, someone else drove it and put gas in it and put 87 in it, could that affect the performance of my vehicle? Before it warmed up good today, it jerked a couple times when accelerating. (the lower grade gas was put in on Sunday)

 

[Molson02536]

...accelerate, then when...? I take my foot off of the accelerator, it makes a noise like if you had a card in a bicycle wheel spoke. It makes this sound on the driver's side. I also noticed that after the car warms up good, the sound mysteriously disappears. What could this be? Also, someone else drove it and put gas in it and put 87 in it, could that affect the performance of my vehicle? Before it warmed up good today, it jerked a couple times when accelerating. (the lower grade gas was put in on Sunday)

NO worries about the 87 octane in your Yukon. That was the recommend octane to be used with your Yukon and any higher octane will have no added performance or mileage to your Yukon due to the low compression ratio to your engine, unless you had your ECM and engine modified to take the higher Octane rated fuel due to higher compression ratio and timing advance to your fuel injection system.

As for the clicking noise you have in the engine bay, you could have a fan clutch going bad and will need to be replaced. Inspect your fan clutch and look for any sign's of damages and replace any sign's of clutch fan failure. Good luck and keep us all posted.