SOLVED: 2004 Suburban metal noise underneath engine

It is our primary vehicle so I think I need to let an expert handle it. Should I be looking for a transmission shop then?

I think you are displaying good judgement, let a shop remove the transmission and the flywheel. You could try the ring gear part of the job yourself if you wanted, but I don’t think you’d save much money on just that part. I think most any good inde shop could remove the transmission for you, no need for a transmission specialty shop. Make sure the shop you choose has someone there who has done it before of course.

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You replaced the starter, but the noise continuous. One would think that you do not have a starter or flywheel problem.

We don’t have a picture of the flywheel to judge its condition, but if the engine starts it seems to work, even with worn down flywheel teeth. Once the engine starts the starter gear is retracted and there is no more contact with the flywheel. Doesn’t this mean something else makes this noise?

You are planning for a lot of work dropping the transmission and replacing the flywheel when it may not make a difference in the end.

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Valid point, but the noise got better. I am out of my league at this
point. I will be dropping it off today for a guy to check out.

Why not just put this thing up on jacks, on all four. Then you can put it in gear and listen to the sound. Would be easier to find it this way then guessing.

Edit: if you still feel it’s your starter/flywheel, simply insert a 1/8" spacer between the starter and bellhousing. This widens the gap between the flywheel and starter gear when retracted. If there was continuous contact between the starter and flywheel it should definitely stop now.

Because I do not have jacks that are made for the Suburban. Mine are for when I used to have a small Honda. I am dropping it off today and will let you all know what the shop folks say. I am admitting defeat at this point.

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take the beast to a street with a downhill slope. Turn the engine off, put the transmission in neutral and let the car roll downhill. If the noise continues you have suspension/wheel problems. At least you can narrow down the source.

Edit: make sure you can still brake in time.

I feel confident that it is either a warped flywheel, or the exhaust manifold (where it is missing a bolt). I lean more towards the warped flywheel or something loose within there because it does it when going up a hill consistently but going down stops the noise and not pressing the gas stops the noise. It never makes the noise unless I press the gas and it is worse at cold start but that is because we claim a massive hill to get out of our driveway. Even after warming up a hill will cause it to make the noise. Same for bumps too. If I go over railroad tracks or a messed up pavement then while bumping along and pressing the gas I will get the sound again. Once over it then it will do it a little until we level off for a few seconds.

Well, then do what I suggested, insert a 1/8 or even thicker spacer between the starter and flywheel. If you are right, it’s a cheap and easy fix. However, I would find it hard to believe that the flywheel is warped.

Do you have a way to record the sound and post it here?

I can’t figure out how to attach anything. It may be the computer I am on is not showing me all the options for posting.

select the up arrow icon on the reply form, to the left of the bullet list icon

Wasn’t the starter. Although there were metal shavings and the starter had some teeth damage along with the flywheel, I still have the noise. I am embedding a link to a video on YouTube that has the noise. Checked the u-bolts manually but got no play. I listened with the hood up where the bolts are missing on the exhaust manifold and it definitely was not coming from there. It is more underneath where the transmission is. Video of noise from outside of vehicle

Video of noise from outside of vehicle. I couldn’t attach a mp4 file that I could find. Just pics. https://youtu.be/L8bLd2gWtkc

Thanks,

Keith

My WAG heat shield.

sounds like something is hitting the axle. Check for lose metal covers, heat shields, etc. Could also be the brake dust shield making contact with the rotor.

So I do not believe it is the exhaust system at all. I had the hood up to listen while riding on the front at the point on the exhaust manifold where the one bolt is missing and the noise was no where near it. After moving positions a few times it sounds like it is coming from the rear of the vehicle or possible the aluminum drive shaft (I think that is what it is called). The u-joints look great while moving. No play. Is there something inside the aluminum drive shaft that could make this noise (see youtube video https://youtu.be/GMBuwIoGJKk) when applying the gas only and when extra torque is needed?

New video: https://youtu.be/GMBuwIoGJKk
Is there something in the aluminum shaft that runs between the transmission and the rear differential that could only make noise when accelerating and needing extra torque?

The noise from the driveshaft is the universal joints grinding.

@kurtwm2010 @Yosemite @Barkydog just don’t want to the guys tomorrow to take advantage of me and tell me I need a new transmission or something like that when she shifts perfect, has plenty of power, and just doesn’t have any gear issues. Heat shields are all tight and snug. Rear rotors and brake housing looks fine. No loose parts anywhere. It something with that drive shaft which is what @Nevada_545 is saying, the drive shaft just echoes noises that make it to it. So if it is the u-joints grinding then that should be pretty easy, right?

It shouldn’t take long to remove the drive shaft, you will be able to feel the binding universal joints by hand.