I found a busted off bolt head on top of my skidplate ?

[Yetti]

yep GM uses almost all the bolts configred like that. if the bolt is silver colored I would assume it came from something like the diff. if its a black colored bolt I would look higher up at engine mounts assorery drives and other stuff higher up.

[pdsq99f4]

Check the rear bolt on the exhaust manifold where it bolts to the head. On the numerous head jobs I've done, about 1/3 can't get the exhaust manifold to bolt back up because the #5 runner warps. Usually this results in a broken bolt and exhaust leak.

[fourfourto]

I checked those bolts (at least the ones I could see)
I also have the original head and no work was done in that area.

[pdsq99f4]

You have to remove the shield. They just break sometimes on their own. On many of the heads I've replaced the bolt head has already fell off or breaks off as soon as you put a wrench on it. It's all caused by the exhaust manifold warping. Is it still under warranty? If not, good luck drilling it out. Real PITA.

[fourfourto]

Thanks,Im at 39k .Next oil change Ill do at 45k (mobil 1 syn ex perf) and I will do a complete inspection.