My stepson just scored a decent 2007 HHR 2LT. We are working through all the issues with the car and this site has been a huge help. The car came with the 2.4L motor but the previous owner did an engine swap. I'd like to be able to confirm that a 2.4L was installed and not a 2.2L. Are there any visual clues to be able to confirm this?

Other issues that this car had:
sunroof leaked like a sieve. Way out of adjustment and both rear drains were disconnected when the tubing shrank.
Gauge cluster was broken, prev. owner swapped it for one with 300K on the odometer. I was able to repair the original cluster. (114K)
Horn (clockspring)

All in all, it's a decent car that should last him a long time.

 

A 2007 2.4L will have VVT on the cam cover and VVT valves. The 2.4 has coil on plug, the 2.2 has a ignition control module on top of the spark plugs. The 2 engines use different ECMs.
The odometer data is stored in the BCM. If you replace the cluster without using a computer to match it the odometer display will be frozen. So, whatever was on it when you got it was on it when it was installed. Unless somebody did something strange, you original should be accurate.
The purists around here will correct you, 2LT.

 

I thought only the 2006 2.2 had the ignition control module.

Even if it has VVT, you still won't know if it's a 2.4, because the later model 2.2 have VVT also.

 

2006 and very early 2007 2.2 came with an ignition coil module.
if there are bar code stickers still on the head or valve cover that should have the L61 (2.2) or LE5 (2.4) designation.