I recently replaced the exhaust gasket on my 2006. Has anyone else had to do this? I am curious to know how common it is for one to go out. I replaced it about 2 years ago when I replaced the head gasket, read more here: https://www.chevyhhr.net/forums/problems-service-repairs-42/disappearing-coolant-39502/

2006 HHR LT
191000 miles

If there is a discussion on this already, leave me a link.
THANKS

 

If you're referring to the exhaust manifold gasket, I couldn't find a thread on that. But they can fail if the gasket was of "so-so" quality, or the nuts holding the manifold to the head were unevenly tightened.

You may want to double check as a leaking flex pipe can mimic a leaking manifold gasket.

 

One question.
Did you tighten the exhaust manifold down using the appropriate torque settings? And did you check or retorque it after a few hundred miles? Always a wise thing to do after a few heat/cooling cycles on replaced exhaust gaskets.
Also, not sure if there is a tightening sequence on these but in general you tighten them from the center bolts working outward.

In the old days, if you put headers on your V8, they were notorious for getting loose once the gasket shrunk a little from the heat.

 

I had to replace my OE gasket. It was actually rusted. I had a CEL and that was one of the things I had to do to fix it.

 

What is the torque on those nuts? I haven't smelled any exhaust coming through the vents since we replaced it.

 

for the 2.4L:
Exhaust Manifold to Cylinder Head Nut...... 14 N.m 124 lb in
Exhaust Manifold to Cylinder Head Stud.... 10 N.m 89 lb in
Exhaust Manifold Pipe Flange Stud ........... 16 N.m 12 lb ft

 

I was talking about the flange gasket, BTW.