Quite a few of us with aftermarket radiator has been noticing that takes a lot of effort for the car to warm up on a really cold days, especially on the highway with a lot of airflow through the engine bay. This thread on N54tech described the problem pretty well: http://www.n54tech.com/forums/showthread.php?t=35394


My guess is that the DME is allowing too much flow through the more efficient aftermarket radiator. Doesn't seem like a stuck thermostat for me, since the car warm up as long as it is not crazy cold out there (like sub zero of single digit F) or I stick to mostly city driving with doesn't allow tons of airflow through the radiator. Just wondering anyone has any idea what's the duty cycle settings for water pump in low-temp operation and has anyone discover the tables for waterpump speed so we can adjust it through reflashing the car?


Or is taping up the front grilles with masking tape is the only viable solution for now, which is what I have been doing so far for the last few weeks...