2006 Hummer H3

Engine Mechanical problem
2006 Hummer H3 All Wheel Drive Automatic 31000 miles

3.5. 5 cyl. Vortec engine. While standing by my car I heard a small pop and a tingling sound and then found what appeared to be an exhaust bolt head lying underneath my car. Can't find where the head came from but am positive thats what it was. Bolt head letters appear to say 9.8 on head. What are the chances that I will have have an exhaust leak one of these days if I don't replace? Hummer dealer is 75 miles away even though still has warranty. Thanks much.
January 19, 2010.

Most often, the rearmost exhaust bolt is broken. Every one I see has that bolt broken, or it breaks at removal. Due to expansion and contraction, you will have an exhaust leak, it is just a matter of how noticeable it is. With it being a 2006, you may see a check engine light in the future with a P0300 misfire. There are issues with the cylinder heads on these, at a dealer we do about 3 or so a month, that is down from 3 or so a week in years past. The volume of faulty heads has gone down in our market area. I don't see it being an emergency on the exhaust bolt, unless your warranty is running out of time. You want to get it replaced under warranty, that way if something goes wrong in the bolt extraction and it needs a head, your wallet is not the one sought after for payment.

Jan 19, 2010.
Thanks much and will take your advice asap.

Jan 20, 2010.
Sounds good

Feb 6, 2010.