Engine Whine

[JacobZ06]

Just purchased a 2010 Sierra Nevada Edition Crew cab with 4.8 V8, 26000 km. The engine makes a noticeable whine when you accelerate from a stop. The pitch of the whine drops in concert with RPM changes related to transmission shifting. Confirmed whine is unrelated to the radio.

Reminds me of the old days when an automatic transmission in need of service whined.

Any ideas or is this a characteristic of this engine?

 

[MROY16]

Check your IAC, when the IAC stops working it can create harmonics in the Intake Manifold. Has the truck had an aftermarket computer chip installed? That could also be the problem.

 

[JacobZ06]

Check your IAC, when the IAC stops working it can create harmonics in the Intake Manifold. Has the truck had an aftermarket computer chip installed? That could also be the problem.

I don't believe there is an aftermarket chip. I will mention the IAC as a potential cause to the dealer.

So far I have:

1. Alternator bearing
2. Power steering pump
3. IAC

as potential sources.

 

[JacobZ06]

Update on Whine

Took the truck to the dealer. Turns out the whine is the transmission torque converter. Should be replaced by tomorrow afternoon. Apparently they have had a few of these (4 speed auto trans) go wrong.

 

[nikolaiak2007]

I had the dealer warn me of that when i bought my truck back in '10 (same powerplant you got)

 

[JacobZ06]

Our dealer has done 5 trucks with this same powertrain. Wonder what the problem is. Hopefully it has nothing to do with being manufactured in Mexico. Without warranty it would have cost $1800.