E39 M5 Spark Plug Change

I had a slight hesitation and power loss at higher speeds (70+ mph) on a long highway run during a recent trip. The issue only occurred during what felt like high heat conditions. The temp outside was around 73 F and the hesitation happened about 4 hours into the trip. It went away after a refueling and lunch stop as the car had time to cool off and then reoccurred after another 3 hours during moderate Atlanta city traffic. No check engine light or pending or shadow codes. We decided to change the plugs and inspect the coils to start with. It’s been about 2 weeks since the plug change and the issue has not occurred but then we haven’t had a long highway run yet either. Will continue to monitor and see what happens.
Parts:
BMW BKR6EQUP Spark Plug - NGK 3199 - (8)

[@stevenpower3780]

Did you get an replacment engine or ist head? Because you hava an 03 (2003) mark on your cylinder head ?
BTW nice m5 Content

[@hackjobrepairs8938]

This car came with this engine but I will go check for the mark. I didn’t see that. 🤨

[@q8hektor]

That cover is very annoying 😆