Hey Guys; has anyone else had this noise?

I get a rattle from the muffler at idle with the AC on; very annoying.

I had the car up on a rack and nothing is touching anywhere on the exhaust system, and you can stop the noise by grasping the tailpipe firmly with a glove on of course.

It seems to be something inside the MUFFLER! like a loose baffle?

My HHR is a 2006 2.2 LS with 55K miles.

Does Chevrolet warantee the muffler?

 

Does it rattle with the AC off? It might be the extra load on the engine causing vibrations to run down the exhaust pipe.

It doesn't hurt to call the dealership and ask them. I don't know if the muffler is covered under the powertrain warranty or if it is considered a "wear item"... the dealer would know.

 

Yes, but only during the 3/36 warranty.

Could this be what you are hearing?

https://www.chevyhhr.net/forums/show...31&page=12#112

Or are you sure it's the muffler?

 

i have an exhaust rattle....mine has nothing to do with the ac....it does it most all the time now , at idle , and worse when it is 1st cranked....my oem muffler has been replaced....so it is not the oem muffler , but may have been caused by a slight rerouting of my new muffler.....but it sounds like it is comming from the front.

 

My rattle started as someone here has already posted. At idle with AC on. Turn AC off, rattle went away. I initially thought it was possibly the AC compressor or perhaps a sheet metal guard of some sort. I jacked it up one morning before starting it to check for guards and such before getting the exhaust hot. After close examination of the complete exhaust system, I found no guards that would create such a noise. I did find that if I gave the catalytic converter a good rap with my hand that I could duplicate that rattle noise. It what has happened is the ceramic part of the cat inside has come loose and is rattling inside the metal container it is housed in. This was a very common problem with Ford when they first started using this type of cat. Luckily, emissions related parts are covered under warranty for 8 years or 80,000 miles. Mine is in the dealership right now being fixed. I waited a little too long to take it in because two days ago the ceramic inside the cat came completely apart and blocked the exhaust system causing the SS Flex joint where the exhaust connects to the engine to blow out! Talk about an obnoxious sounding noise! I'm waiting for a call from the dealer to confirm my diagnosis and will post the results when I get them.

 

I think coyote is has it figured out. I have seen lots and lots of catalytic converters come apart and rattle on all types of cars and trucks. and yes the catalytic converter is under warranty under federal law for 8/80.

 

Replaced quite a few on customers 95-98 Jeep Cherokees...

 

Just got back from dealer and they say there is nothing wrong with the CAT and the the non-stock muffler caused the flex pipe between the CAT and the exhaust manifold to fatigue and crack. That muffler (Flowmaster) has been on the car since August 2007. I am going to take the CAT off myself and hand carry it to another Dealership that I trust, but it further away and see if they will warranty it. I'll update my progress as it happens.

 

I took my HHR into another dealer that I've dealt with for many years and the service writter had his manager come and and the three of us put it up on the rack and talked about it. I explained that the initial problem was a rattle coming from the CAT and that I thought that the extra vibrations caused by the loose material inside the CAT had probably caused the fatigue cracks to form on the flex pipe. The manage then inspected the whole exhaust system and asked if the muffler was the only thing that I had changed on the exhaust and that the rest of the system was indeed factory. I told him it was so and he called his boss on the phone and chatted with him for several minutes. He then lowered the car to the ground and turned to the service writer and simply said "Fix It"
Unfortunately, they did not stock a CAT as did no other dealers in the area. The CAT is now on order and I am waiting for a call from the service writer to tell me when it comes in.

 

Mine was also doing it all the time after I initially started hearing it. The first few times I could hear the rattle, I could make it go away by turning off the AC. As the CAT broke apart more inside, it started to rattle more easily and I could not make it go away except to raise the RPM of the engine.