BMW Questions? Ask a BMW Repair Expert for Answers.
How is the coolant level?
are you sure it was properly bled and there is not an airlock somewhere?
The general list of overheat cause is this:
1. A faulty thermostat.
2. A faulty waterpump.
3. A coolant leak or low coolant level.
4. An airlock in the system.
5. A faulty viscous coupling
6. Blocked or damaged fins on the radiator
7. A faulty headgasket (you def do not have this)
If you are positive you do not have any of the above, then you will want to repair the pinhole leak next as there is nothing else obvious or common to check - at this point it is the most / only likely culprit.
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