I just bought an '08 with the 2.2 with 57,000 miles. I bought it in November and had to make a few minor repairs, but couldn't find out why it vibrated at idle. I had the air filter off to replace plugs, which were barley finger tight (and the wrong plugs with a narrow gap), and noticed that the right motor mount looked bad. This is the mount that fails the most, but is the easiest to replace.
Since the mount needed replacing I figured that this would be a good time to also replace the tensioner and belt, and check the bearings in the alternator and compressor at the same time.
I removed the washer bottle and jacked up the engine about 1/2" and removed the mount and engine bracket, which made belt access a LOT easier. The splash shield was loosened (tire removed) but not removed to give access to the crank pulley, that made routing the belt easier. These is also an access hole to let you get a socket on the pulley bolt, you may have to raise or lower the engine to line it up.
Everything went back together and on my test drive I thought the engine had quit at a stop light, the difference was that obvious! If your HHR has the original factory mount on the passenger side there's about a 100% chance that it is sagging. On this car the 2 transmission mounts looked good.
NOTE- there is another engine mount on the driver's side which no one talks about. This mount is much more difficult to get to, and I believe that the passenger side mount has to be loosened to allow the engine to move enough to get it in and out.




NOTE- Remove the top 2 bolts on the bracket and loosen the lower bolt most of the way out, then you can swing the bracket out of the way to get to the tensioner. No need to removed it completely.




Installation complete

 

Good work, thanks for your write up. Motor on!

 

Hint: if the tensioner bolt is not visible in the oblong wheel well hole the mount needs to be replaced.

 

Agreed. If they don't line up by about 3/8" or so the mount is definitely shot.

 

Right in the middle like this brand new one.

 

Have a magnet retriever ready so when you drop the bolt into the channel you can get it back out. That's what I did.

 

To save you dropping a socket into that channel, use a 15mm deep socket and a 12” extension, 1/2 or 3/8 drive.

 

You were lucky! I dropped mine and could not retrieve it. Fortunately GM parts is aware and keeps the bolt in stock, not expensive.

 

This simple tool can be the most important one you have at times. I can't tell you how many times I have used mine to find dropped nuts and bolts.
One time I dropped a clip into the intake manifold of a van I was working on, this tool saved me from having to remove the manifold! $10 on Amazon.
It's also good when changing spark plugs in the HHR.

 

Attach the magnet to the side of the socket, might prevent a dropped fastener!