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Let this be a warming

My BMW 3-Series is not heating up. Would you have any idea what the problem is?

Asked on 28 February 2009 by

Answered by Honest John
Probably a failed engine coolant thermostat. The idea of this is to block the flow of coolant through the radiator (but not the heater) while the engine is heating up so that it heats up faster. Once the engine reaches running temperature the thermostat opens so the engine is cooled by the radiator. I'd guess your thermostat is running open all the time.

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