Yeah, do live readings while the engine is running. I've used INPA/ISTA or DIS. They do a pretty good job for that. You might notice something odd - observe every data point including coolant temp, etc.

All the best!

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'05 E53 X5 4.4i, '97 E39 528, '07 E92 335i, '16 F86 X6M.