Joeworf

I am now the owner of two HHRs. One is a 2006 LT and the other a 2007 LS Panel and both have 2.2L engines. I was wondering if anyone here knew offhand if there were any significant changes in the factory tuning of the engines between 2006 and 2007 model years or in the gear ratios (both are automatics)? Why, you may ask? I'll tell you. From the beginning the '06 seemed a little anemic to me off the line in normal driving but I assumed that was just the nature of the beast for a little four-banger. Then I acquired the '07 and it seems much quicker and have somewhat shorter shift intervals than the '06. Now it could be the weight difference but I doubt it. The '06 seems to spool out over a longer period before upshifting to 2nd than the panel and just doesn't seem as "powerful". Also, I've recently noticed that after driving in city traffic for a protracted period (say an hour) the shift points on the '06 become harsher (harder?) and more pronounced. I'm assuming this could may be heat related since after a stopover period it shifts smoother before resuming to the more noticeable hard shift points, perhaps half an hour later. The engine temperature does not seem to go up. Any ideas? Notions? Similar experiences? Knowledge? Specs? Anything?

Oldblue

There were many improvements to the 07 model year, I'm not sure if transmission was upgraded or just the TCM program

donbrew

The minimum difference is different casting.

The 2006 engine was sort of a bridge from one phase to the next, then again in 2009.

I imagine GoOgle would answer almost any question about it.

Oldblue

The 2.2 engine block is virtually the same since 2003, the head casting has changed, the power steering pump was removed from the intake camshaft and VVT solenoids were added in 2009.
The casting number on our 2003 Sunfire and the 2007 HHR are the same.

donbrew

GoOgle led me to this.

Note the difference in HP and torque.

Oldblue

Right I forgot about the gen II block updates, looks mostly, ignition and cam updates

aradmahogany

Looks like my 2006 2.4 was "ahead of its time" haha

Oldblue

But this is about the L61 and LE5 2.2 not the 2.4

Joeworf

I suspect Aradmahogany was just gloating, Oldblue.
Anyone want to chime in on the hard shift issue mentioned in the initial post about the '06 after it has been running a while? Might as well kill two birds with one stone, right?
Thanks for all the input guys. Looks like the '06 2.2 was just an inferior set up compared to later years. Gotta learn to live with it. At least I now know.

donbrew

Nobody mention the hard shift because it is the second most discussed problem on the site; we are bored and the SEARCH tool will return tons of posts. usually it is a VVT valve going bad. To be sure you need codes.