Exhaust heat shield bolts

[rationull]

Lately I’ve noticed a rattle that I think is coming from one of the exhaust heat shields on my 2011 WRX. During its oil change today, I investigated a bit, narrowing it down to one particular shield (the left side exhaust manifold one) which is held together by 3 bolts. I thought one bolt in particular was the culprit, so I hit it with some PB blaster, broke it loose, and then tightened it again to torque spec from the service manual (14 ft*lbs).

I think the rattle is still there so I’ll probably investigate further this week or next weekend. I’m not sure though whether I’m playing with fire trying to loosen and tighten these bolts given they’re on the exhaust system and I don’t really want to break one. The frequently recommended workaround is to use hose clamps around the shields to tighten them down but presumably that’s more necessarily as the car gets older and the bolts and shields get more corroded from heat exposure.

Thoughts? Are heat shield bolts less of a problem than actual exhaust pipe bolts? Am I overthinking things given the car isn’t very old and I live in dry CA?

 

[tudorart]

I don't think this is a big deal. Breaking a bolt is smth you can avoid if you pay attention.

Subaru heat shields are always going to rattle. You'll be doing this a lot more as the car gets older. Expect becoming an expert on this.

Use the appropriate washers like grower or other lock type washers used on vibrating equipment (motorcycles).

 

[eljefino]

If you're going to break these loose, slather 'em in anti seize before you put them back together. Now's a great time and use tudorart's snazzy washers.

 

[Trav]

Try spring washers under the bolt heads and use never seize on the threads.
Edit: I see salt belt residents think alike.

 

[dparm]

The shields themselves are probably rattling. This is a common problem on lots of cars.

My suggestion is to smack them with a rubber mallet a few times. Sometimes a very slight tweak is all you need to silence it.

Not sure where the shield is exactly, but some of those can pretty much be removed without any problems.

 

[Vikas]

Isn't this thing still under warranty?