Since the weather is supposed to be decent (44 and NOT snowing) this weekend, I would like to investigate a problem that started approx. 3 weeks ago.

I have had my 2008 HHR since October have have enjoyed the 11,000 miles I've driven it it so far. I installed a CAI in December to give it a little more passing power, fixed my flaking-chrome shift knob and am ready to tackle some other maintenance projects soon (brakes, plugs, etc).

My current problem is a hissing/raspy sound that occurs under acceleration. It drives me nuts! My first thought was that the cold air intake had a loose clamp or other issue. I verified that everything was still in its correct place and tight. Now, I am thinking that its on the exhaust side.

What should I check first? How do I know where the exhaust leak is coming from? Do HHRs have any known issues with exhaust manifold gaskets? Are there any weak spots in the exhaust manifold/pipes?

I've also noticed that I have a hot metal smell coming from under the hood somewhere- yet I am having a hard time isolating it! I can smell it after a good run on the freeway. Just puttering around town doesn't get the engine/engine bay hot enough. It is not the brakes (thought a caliper was dragging), it does not make any additional noise (such as a beating that is going bad) and I don't notice any decrease in performance. Maybe there is an exhaust leak and its heating up something that shouldn't be?

Any help would be appreciated - in the meantime, I will start detailing it! After a long, harsh winter...it needs it!

Thanks in advance,

Christine
2008 LS 5-speed (built as an OnStar demo vehicle), leather, sunroof, K&N CAI, and every option I can think of! An oddball HHR...

 

Flex joint on the downpipe almost for sure. Take the air cleaner off, look down behind the engine, get your extremely long and delicate fingers down around the underside of the flex portion and feel around for sharp edges.

The pipe is real easy to replace, but expensive, since it is the catalytic converter. There are aftermarket repair parts that will require a skilled tech to install (cutting and welding), but you will not need to go through it again.

You might check into the Federal Emissions Warranty, I think that you are probably on the edge, or over. A dealer could verify.

 

have someone hold a rag on the tailpipe while you listen up front..if your flex pipe is leaking you will know real quick

 

Thanks! I'm heading outside now to see if that's the problem. What kind of welder/settings would you use to weld it? I read another post that says once you drop the assembly out, it is not hard to weld. It will be SO nice to have it fixed!

 

here ya go, in case you need some extra pointers...

https://www.chevyhhr.net/forums/how-tutorial-library-21/how-repair-flex-pipe-31536/

 

The welding in question is removing the old flex joint and flange and then welding the new joint and flange onto the old pipe. You cannot weld the hole. search ebay for "hhr flex pipe" there are several available around $40. I see that a Canadian company has made it even easier, if you have an automatic. And there are a few entire cat pipes for a reasonable amount of money. It might be worth it to go across a bridge.