Exhaust manifold bolt breaking?

[OrangeCrush]

I gotta go into the shop this morning to pull the left exhaust manifold. The rear bolt head is broken off. I'm not sure why but the head of it is just gone now causing an annoying exhaust leak until it gets warm and expands.

I went into the dealership to pick up a couple of gaskets and replacement bolts. (THAT's how I ended up buying that damn light bar... shoulda never walked into a place that sells "stuff")

Anyway, talking to a tech there, he mentioned he has replaced a few of them for the same thing.

Anyone ever heard of that? I'm just hoping like hell when I pull the manifold, the remaining stud that is sticking out doesn't break off flush.

Mark

[OrangeCrush]

Got it done... took about 2 hours. Pretty simple, just time consuming spinning what's left of the broken bolt with a pair of visegrips.

take the wheel off and remove fender liner.




Undo the 6 bolts holding on the exhaust manifold. You can reach them through the inner fender. I also undid the 3 bolts connecting the exhaust manifold to the exhaust pipe. (this will allow you to slide the manifold to one side out of the way)




Though not a great pic, the bolt you see is the one closest to the firewall. The head was simply missing.



Here's the culprit... little bastage

[Chrmer3]

Both my exhaust manifolds had the rear bolt head broke off. Unsure what is causing this but its not just on the hummers, the chevy garage had a tahoe in there with same rear bolt broke off.

Mechanic did same as you used vise grips to unscrew the stud (rest of bolt-head= stud) out.

If you hear an exhaust tick be assured its a broke bolt-
Chris

[Garry]

Just had the same thing happen to me with my exhaust manifold bolt(s).
I have 79K on my 04 and started hearing a sound like air escaping on
start-up. After some time the sound goes away. Upon inspection I found that my
exhaust manifold bolt had completly snapped off and only a small
part of the treads remain.

I located the bolts at a local fastenal dealer - here is the link for anyone interested.

http://www.fastenal.com/web/products...1115929&ucst=t

These are Grade 90 bolts but you can also get the 10.9 Grade but since I
am going to all of the trouble to replace them...........for $18 who cares.
I would rather use Grade 90 and be done with it.

Appearently this is a common problem with H2s. Little did I know.

[Hellz]

i had this problem somewhere about the 70k mark for my H2.
i had done alot of research prior to that and recognized right away what the issue was when it happened.

my H2 was still under the extended warranty then, so had no problems, but i imagine it will pop its head again at some point unless they used higher quality bolts.. and if they did, i doubt they repalced all of them on both sides.

[Olfart]

at about 48,000 my 2004 went in to replace the power steering pump and idler and pitman arms. They noticed that there were 2 broken ex manifold bolts. I had never heard any hissing or other sounds indicating a manifold leak and I'm not sure which bolts they were. But in order to extract one of them they had to pull the head to get a straight shot at it. Luckily I still was under extended warranty, but the truck was in the shop for a week.

[OrangeCrush]

I gotta go into the shop this morning to pull the left exhaust manifold. The rear bolt head is broken off. I'm not sure why but the head of it is just gone now causing an annoying exhaust leak until it gets warm and expands.

I went into the dealership to pick up a couple of gaskets and replacement bolts. (THAT's how I ended up buying that damn light bar... shoulda never walked into a place that sells "stuff")

Anyway, talking to a tech there, he mentioned he has replaced a few of them for the same thing.

Anyone ever heard of that? I'm just hoping like hell when I pull the manifold, the remaining stud that is sticking out doesn't break off flush.

Mark