Expert: Stephen Sokol - 3/27/2007

Question
Hi I have an alfa 156 V6 2000 W. It Keeps overheating, I have had a new radiator , thermostat and replaced both head gaskets. it only overheats whilst driving and cools down rapidly when stationary. The fans come on whilst driving and stop when stationary. I have been told there might be an air lock, is this correct and if so how do i get rid of it.

Answer
Based on what you wrote: the V-6 is self bleeding if all the plumbing is as designed. You can check for an air lock by loosening a heater hose. However, check first in which direction the air flows when the fan is on. With vehicle parked activate the fans and hold your hand over the fan and make sure the airflow goes towards the engine. If that is correct then you must have a faulty water pump.