Engine Noise

[Teamwieland]

2013 Yukon XL making strange noise at idle (not sure when driving). Seems worse if on a slight incline like pulling into driveway. Seems like coming from bottom of motor, maybe back around flex plate, but hard to say for sure.

Video:

 

[mikez71]

Check your starter. Is it noisier on passenger side? Sounds like the gear is loose or not retracting fully.
That would explain why on an incline the noise is louder, the gear maybe sliding towards the flexplate more..

 

[Dustin Jackson]

I second the starter gear is probably contacting the flywheel.

You can test by parking with the rear of the Tahoe uphill with the nose pointing downhill and if the problem doesn’t happen when parked like that I think you’re on the right track

 

[Teamwieland]

Thank you. Will give that a try. I can pop the inspection cover as well and see if I can visually verify that.

 

[Teamwieland]

Correct on the starter gear making the noise. Guessing only remedy is to replace the starter. Is it harmful to run the motor with that noise (ie premature wear on flex plate teeth?).
Interestingly, I popped the bell housing inspection cover and this nut fell out. Initially thought that is what was making the noise but apparently not.

 

[Dustin Jackson]

I mean you’ve been driving it up until now and it’s been fine but when you understand it’s the teeth of the flywheel grinding against the teeth of the starter it’s not a great picture.

Interested to hear what that bolt goes to, I don’t have any experience working on that side of the motor

 

[mikez71]

I once had the starter gear come out of the starter on a toyota sequoia.
Clanged around the bellhousing on the drive home real good.. Didn't destroy anything else surprisingly.