I could tell if engine was below 150 or maybe even 160, the problem was it never got to operating temp unless the ambient was about 90°F. For many months the ambient temp was high enough for the engine to hit the magic buffer zone of 160° to tell me "all good" but the engine performs poorly at 160F.

I bought the car in April and the problem didn't show up until December when ambient was cold enough to keep coolant temp below 160 but by then it couldn't even keep it 100. I drove dozens of times between child of and Racine not knowing my coolant was 20-30° too low because of the buffer on the temp "estimator" on the dash telling me the engine was at operating temp for multiple 1000s of miles.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)