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Old 01-10-2013, 08:25 PM
Droptop85 Droptop85 is offline
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Location: Fresno
Join Date: Oct 2011
Posts: 351
Mein Auto: 03 Z4 3.0i
These cars have a fail safe thermastate. Once the thermastate reaches a certain amount of high psi it is forced open. This explains the engine overheating and then cooling down a bit. I would replace the thermastate, water pump, and exansion tank at the same time as these typically all fail at the same time.
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