Wife’s Suburban started whining in 4 wheel auto but is whisper quiet in 2wd. Did not venture into 4 wheel hi or low. Just ran it in 2wd until had to go to the dealer for service next time.
Well started noticing oil on the garage floor here the past week.
Took her in today. Oil pan gasket is bad must swap the oil pan and not just the gasket.
Not really a big deal at the moment as it is a warranty replacement.

As for the metallic whining noise that is perfectly normal.

This will be my 5th vehicle that has 4wheel auto (not AWD) and NONE make any extra noise in 4 wheel auto when the front wheels aren’t activated. NONE, my 2000 Silverado does not make a lick of noise.
4 wheel hi and low yes, auto no.

Guess I will give her the Amsoil treatment and see if she shuts up.

Good to hear that this is warranty work.

Not sure how any noise as you described would be 'normal'.

I've had a few auto-4wd GM products and I agree they should not make more sound in auto unless 4wd is activated. I would change the front diff and transfer case fluid and see if that helps. Could be a clutch in the transfer case grabbing. I like Amsoil also. To test, put it in auto and try to turn in a parking lot. If crabbing it is definitely in 4wd and likely a transfer case issue.

quote:

Originally posted by sigmonkey:

That was my go to solution in my teen years

I could be wrong about these observations, since my experience is with older models. Verify with your shop/owner's manuals.

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Oil pan gasket is bad must swap the oil pan and not just the gasket.

Is the gasket molded into the oil pan now, or what? They used to be just RTV (silicone).

As for 4wd auto, are you using this on dry pavement? When you select this, the power flow through the transfer case is the same as in 4wd high. The "auto" part is the front axle coupler. This is needless wear on the t-case if you aren't driving on slippery roads. If you aren't doing this you should select 2wd. As for Amsoil products, verify compatibility, because this t-case (again, unless they changed it) should use GM AutoTrak.

Get it in writing that you have reported the noise under warranty. That is not normal.

quote:

Originally posted by egregore:
I could be wrong about these observations, since my experience is with older models. Verify with your shop/owner's manuals.

quote:

Oil pan gasket is bad must swap the oil pan and not just the gasket.

Is the gasket molded into the oil pan now, or what? They used to be just RTV (silicone).

As for 4wd auto, are you using this on dry pavement? When you select this, the power flow through the transfer case is the same as in 4wd high. The "auto" part is the front axle coupler. This is needless wear on the t-case if you aren't driving on slippery roads. If you aren't doing this you should select 2wd. As for Amsoil products, verify compatibility, because this t-case (again, unless they changed it) should use GM AutoTrak.

Not sure really. When I asked the issue he said it was leaking at the pan so they replaced it. I asked if the pan was cracked and he said no they just replace the pan anymore when it leaks.

I had not checked required fluids just know Amsoil quieted up my rear on the Explorer I used to have.
I’ll check the manual for the fluid recommendation. Amsoil suggests their transmission fluid.

As for driving in 4wheel Auto it should not make this much noise when not engaging the front wheels in my opinions. My 2000 Silverado makes no noise, my old Explorer made no noise, my current Expedition makes no noise.
My father in law has a 2017 Suburban I need to take a spin in it and see how his sounds.

There should not be an issue driving in 4wheel Auto all the time.

quote:

Originally posted by JD DRIVER:
Get it in writing that you have reported the noise under warranty. That is not normal.

It is on the repair sheet for the oil pan. I am going to take a spin in the in laws and see how it sounds. If it is quiet like I expect it will be I will press the issue more. Current Covid stuff they are working on a skeleton crew and don’t feel like arguing at the moment.