I went to change out my stock plugs this morning to the Bosch #4482 +4s that have gotten such good reviews lately. I snapped a few pictures to show how easy this is on the Ecotec 2.2.
Once you get the intake off this is what everything looks like. The plugs are under the black plastic cover in the middle of the motor. The plug on the right side has to be disconnected. It is a two part disconnect, the grey part of the tab moves first and then you release the black clip and it slides right off. There are 4 bolts which hold down the cover, remove them, and lift the cover off.
This is the spark plug cover and the spark plug boots. You'll notice, no long stringy spark plug wires to deal with here.
Here is the motor minus the plug cover. The spark plugs are down there in those holes. In case you have not worked on a motor with deep plugs before, DO NOT let this intimidate you.
Here are both plugs side by side. The stock plugs shown here have 14,000 miles on them.
This picture shows my plug socket on the end of a 6 inch extention to give you an idea of where the plugs are in realtion to the top of the holes.
IMPORTANT TIP #1: I'm sure there are different tools and methods for getting to deep plugs, here's how I do it.
I use two spark plug sockets, one with the rubber insert and one without. The one with is used to remove the plug. Next I push the new plug far enough into the rubber insert to hold the plug while I start it by hand. Once I feel the threads take hold I pull out the socket with the rubber insert and change to the socket without the insert. The socket without the insert will not try to grip the top of the plug, it is only used to tighten up. This makes it easy to remove the socket from the hole without a fight.
IMPORTANT TIP #2: If you try to remove the socket with the rubber insert and it will not let go of the spark plug. DO NOT PANIC, the socket will not be stuck in your engine forever, just flip your rachet the work in the opposite direction and remove the plug and try again. Switch to the plug without the insert sooner next time.
I used anti-sieze on the plug threads and boot goo on the plug boots. Once you've changed all the plugs, reassemble in reverse order. I could tell an immediate change in my mid-range power.
I've changed plugs on many types of cars/trucks and the HHR was a simple straight forward job. The parts were easy to access and remove, no maze of wires to work around, no fuel rails in the way. Easy job in my opinion.