If the MIL is lit at any time, there is a code stored. What does the dealer say the code is?

Do you have access to a quality scan tool or other device that can show EOT, ECT, TFT? Maybe you have an overheat issue.

__________________
Dave

'05 325xi
'10 E70 35d
'85 911 Carrera
'66 911 Work in progress
'91 Chevy C1500
'95 Jeep Cherokee
‘18 Jeep JLU