Noisy Yukon Denali

[Denalievv]

Hello all, first post here... I bought a 2010 Yukon Denali XL about a month ago with 81k on it. I took it to the dealer because it said to service brake system and they said it needed a new brake booster. They put the new booster on and when I picked it up and started to drive away it sounded like there was a loud air rushing sound coming from the engine on the drivers side. You can't hear it at idle, but gets louder with speed under power.

They said its normal even though it wasn't there when I dropped it off. They said they would check it again and said its coming from the power steering pump. I listened through a stethoscope, and it is definitely loud, but could that really be it going in a straight line? Also, could there be any way that replacing the brake booster could affect that?

Thanks for any help!

 

[Denalievv]

No ideas? The dealer replaced the power steering pump and the noise didn't change.

 

[Ryno21]

You said it gets louder with driving, does it get louder with engine rpm? Does yours have the electric fans or fan clutch?

It's possible they messed up the seal through the firewall or your clutah fan is bad. I can't see how it would be power steering related.

 

[Denalievv]

I'm not sure on the fans, but it does it even when fans are not on.

The sound level increases with engine rpm. So if I give it some gas to get to 30 mph it gets louder, then when I hit speed and back off I don't hear it.

 

[dubyagee01]

I would check and see if they neglected to reinstall any sound deadening or firewall plugs under the dash


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[Denalievv]

The dealer is still saying the noise is normal even though it wasn't there before. It is coming from the driver side in the engine compartment.

It is loud enough to hear over the radio if you listen for it. It's loudest if you go slow and tap the pedal a bit then let off.

 

[CrashTestDummy]

The noise IS the brake booster. NOT normal on these trucks. Like others have said, perhaps they left some gasket or sound deadener out when replacing the booster. Why did they replace the booster, anyway??. Those things hardly ever go bad. Master cylinder, sure, after many years of abuse and neglect, but rarely the booster.

 

[Denalievv]

They had apparently replaced it before I bought it. Then after I bought it on the way home it got a code. They said it was the booster so they replaced it again and when I picked it up I noticed the noise.

Any ideas on how I can prove its the booster?