I was cleaning up my engine today, and I noticed something I hadn't seen before.

My cylinder head has a small blue plus sign painted on the front of it, over the stamped number in the head.

I was curious if anyone else had seen this on their engines, and do they know what it means.

I'm guessing it's a mark the dealer put on, signifying the cylinder head was updated...or at least I hope. My truck only has 85k on it, so I'm always fearing the illusive head meltdown. Since our engines tend to have the occasional cylinder head issue on the earlier motors.

Hopefully someone can drop some knowledge on me on this marking.

Very respectfully,
Shane Clarke
MAJ, US ARMY

2006 Hummer H3